XJ650R (Seca) Service Manual


Chapter 1, Introduction


This manual was written by the XJ Owners Group to replace the confusing system of supplementary manuals issued by Yamaha. It is not possible to put an entire mechanic's education into one manual, so it is assumed that persons using this book to perform maintenance and repairs on Yamaha motorcycles have a basic understanding of the mechanical concepts and procedures inherent to motorcycle repair technology. Without such knowledge, attempted repairs or service to this model may render it unfit for use and/or unsafe.

This model has been designed and manufactured to perform within certain specifications in regard to performance and emissions. Proper service with the correct tools is necessary to ensure that the motorcycle will operate as designed. If there is any question about a service procedure it is imperative that you contact a Yamaha dealer or the XJ Owners Group before continuing.

Particularly important information is distinguished in this manual by the

following notations:

NOTE: A NOTE provides key information to make procedures easier or clearer.

CAUTION: A CAUTION indicates special procedure that must be followed to avoid damage to the motorcycle.

WARNING: A WARNING indicates special procedures that must be followed to avoid injury to a motorcycle operator or person inspecting or repairing the motorcycle.

Starting Serial Number XJ650RJ .............5V2-0000101



The proper special tools are necessary for complete and accurate tune-up and assembly. Using the correct special tool will help to prevent damage from improper tools or improvised techniques.


A. For Tune-up


1.   Compression gauge


2.   Timing light


3.   Tachometer


4.   Tappet adjusting tool P/N. 90890-01245-00

This tool is necessary to replace valve adjusting pads. This can also be used for the XS750, XS850 and XS1100.


5. Vacuum gauge


P/N. TLU-11080-30-02

This gauge is needed for carburetor synchronization.


B. For Engine Service


1. Clutch hub holder P/N. TLM-90910-42-00

This tool is used to hold the clutch when removing or installing the clutch boss lock nut.


Valve guide reamer P/N. 90890-01227-00

This must be used when replacing the valve


3. Valve seat cutter



This tool is needed to re-surface the valve seat.




4. Valve guide remover P/N. 90890-01225-00

This must be used to remove the valve guides,


5. Valve guide installer P/N. 90890-04017-00

This tool is needed for proper installation of the valve guides.


6. Valve spring compressor P/N. 90890-01253-00

This tool must be used for removing and installing the valve assemblies.


7. Piston ring compressor P/N. 90890-04044-00

This is used to compress piston rings when installing the cylinder.


8. Piston base


P/N. 90890-01067-00

Use 4 of these to hold the pistons during cylinder installation.


9. Rotor puller


P/N. 90890-01080-00

This tool is needed to remove the A.C. Generator rotor.


10. Rotor puller attachment P/N. 90890-04052-00

This tool is needed when removing the A.C. Generator rotor together with the rotor puller.


11. Rotor holding tool P/N. 90890-04043-00

This tool is used to hold the A.C. Generator rotor during removal and installation.


12. Dial gauge stand


P/N. 90890-01258-00

This tool is needed to hold the dial gauge.


13. Dial gauge


P/N. 90890-03097-00

This dial gauge is used to determine piston position for correct timing.


C. For Shaft Drive Service


1. Middle drive pinion holder P/N. 90890-04051-00

This tool is needed when measuring gear lash.


2. Middle and final gear holding tool P/N. 90890-01229-00

This tool is needed when measuring gear lash.


3. Gear lash measurement tool (Final gear) P/N. 90890-01230-00

This tool is needed when measuring gear lash for final gear.


4. Final gear holding tool P/N. 90890-01254-00

This tool is needed when measuring gear lash.


5. Damper compressor P/N. 90890-04011-00

This tool is needed to disassemble and reassemble the middle gear damper.


6. Middle drive shaft nut wrench P/N. 90890-04045-00

This tool is used to loosen and tighten the drive shaft nut,


7. Middle drive shaft holder P/N. 90890-04046-00

This tool is needed when loosening and tightening the drive shaft nut.


8. Drive pinion bearing retainer remover P/N. 90890-04050-00

This tool is used to loosen and tighten the final gear drive pinion bearing retainer.


9. Armature shock puller (M10 x 1.25) P/N. 90890-01290-00, 90890-01291-00

These tools are used to remove the final gear drive pinion.


10. Crank installer adapter (M10x1.25/M14x1.5) P/N. 90890-01277-00

This adapter is needed when using the armature shock puller.


11. Drive shaft puller P/N. 90890-04012-00

This tool is used to remove the drive shaft.


12. Slide hammer


P/N. 90890-01083-00, 90890-01084-00

These tools are used to remove the drive shaft.


13. Front fork cylinder comp. holder P/N. 90890-01300-00

This tool is used to loosen and tighten the front fork cylinder comp. holding bolt.


D. For Electrical Components


The uses of these tools are described in CHAPTER 6. 1. Pocket tester


P/N. 90890-03104-00

2. Electro tester


P/N. 90890-03021-00





This chapter includes all information necessary to perform recommend inspection
and adjustments. These preventative maintenance procedures, if followed, will
insure more reliable vehicle operation and a longer service life. The need for costly
overhaul work will be greatly reduced. This information applies not only to vehicles
already in service, but also to new vehicles that are being prepared for sale. Any
service technician performing preparation work should be familiar with this entire chapter.


Periodic Maintenance Emission Control System






1,000 km or 1 month (600 mi)

5.000 km or 7 months (3,000 mi)

4,000 km or 6 months (2,500 mi)

8.000 km or 12 months (50,000 mi)


Cam Chain

Adjust chain tension.






Valve clearance

Check and adjust valve clearance when engine is cold.






Spark Plug

Check condition. Adjust gap. Clean. Replace after initial 13.000 km (8.000 mi) or 18 months and thereafter every 12.000 km (7,500 mi) or 18 months




Replace every 12,000 km (7,500 mi) or 18 months





Check ventilation hose for cracks or damage. Replace if necessary.






Fuel Line

Check fuel hose (and vacuum pipe) for cracks or damage. Replace if necessary-






Exhaust System

Check for leakage. Retighten as necessary. Replace gaskct(s) if necessary.






Idle Speed

Check and adjust engine idle speed. Adjust cable free play if necessary.






Carburetor Synchronization

Adjust synchronization of Carburetors.





• It is recommended that these items be inspected and service by a Yamaha Dealer or other qualified mechanic.

General Maintenance/Lubrication







1,000 km or 1 month (600 mi)

5.000 km or

7 months

(3.000 mil

4,000 km or 6 months (2.500 mi)

8.000 km or 12 months (5.000 mil

16,000 km or 24 months (10,000 km)


Engine Oil

Warm-up engine before draining

Refer to NOTE







Oil Filter









Air Filter

Clean with compressed air. Refer to NOTE:








Brake System

Adjust free play. Replace pads if necessary. (Front) Replace shoes if necessary. (Rear)









Adjust free play.








Final Gear Oil


SAE 80 API "GL-4" Hypoid gear oil







Control and Meter Cable

Apply chain lube thoroughly

Yamaha chain and cable lube or SAE 10W/30 motor oil







Rear Arm Pivot

Check bearings assembly for looseness. Moderately repack every 16.000 km (10.000 mi)

Medium weight wheel bearing grease







Center and Side, stand Pivot!

Apply lightly.

Yamaha chain and cable lube or SAE 10W/30 motor oil







Front Fork Oil

Drain completely. Refill to specification.

Yamaha fork oil 10 Wt or equivalent







Steering Ball Bearing and Races

Check bearings assembly for looseness. Moderately repack every 16.000 km (10.000 mi)

Medium weight wheel bearing grease







Wheel Bearings

Check bearings tor smooth rotation. Replace if necessary.









Check specific gravity. Check breather pipe for proper operation.








Change/Brake Pedal Shaft Pivol

Apply lightly.

Yamaha chain and cable lube or SAE 10W/30 motor oil.







A.C. Generator

Replace generator brushes.

Replace at initial 13.000 km (8.000 mi) and thereafter every 16,000 km [IQ.OOOmi)








Brake/Clutch Lover Pivot Shaft

Apply lightly

Yamaha chain and cable lube or SAE 10W/30 motor oil.






* It is recommended that these items be inspected and serviced by a Yamaha dealer or other qualified mechanic.


1) Engine oil type

2) Air Filter

The air filter should be cleaned more often than specified intervals if the machine is operated in extremely dust areas.

Engine Maintenance


A. Valve Clearance Adjustment




Valve clearance must be measured with the engine and at room temperature.

1.    Remove the seat and fuel tank.

2.    Remove the horn, flasher relay, and spark plug lead wires.

3.    Remove the cylinder head cover and left crankcase cover (pick-up base cover). Care should be taken to not scratch or damage the gasket sealing surfaces,

4.    Turn the crankshaft with the nut on the left end of the crankshaft to turn the cams. The proper position of the cam when measuring the valve clearance is with the cam lobe directly opposite the valve lifter.

5. Insert a feeler gauge between the valve lifter and the camshaft base circle.

Intake valve clearance (cold):



0.15 mm

(0.004 ~ 0.006


Exhaust valve clearance (cold):



-0.20 mm




Valve clearance is adjusted by replacing the adjusting pad on the top of the vale lifter. Adjusting pads are available in 25 thicknesses ranging from No. 200 (2.00 mm) to No. 320 (3.20 mm) in steps of 0.05 mm. The thickness of each pad is marked on the pad face that contacts the valve lifter (not the cam). Adjustment of the valve clearance is accomplished as follows:

1.    Determine valve clearance (feeler gauge measurement.)

2.    Remove adjusting pad and note number.

3.    Select proper pad from appropriate chart (intake or exhaust chart).

4.    Install new pad and check installed clearance.


1.    Measure valve clearance. If clearance is incorrect, record the measured amount of clearance. This must be measured carefully.

2.   There is a slot in the valve lifter. This slot must be positioned opposite the blade of the tappet adjusting tool before the tools is installed.

3.    Turn the cam until the lobe fully depresses the valve lifter and opens the valve. Install the tappet adjusting tool as shown to hold the lifter in this depressed position.


The tappet adjusting tool is fastened to the cylinder head securely using an alien screw. Make sure that the tool contacts the lifter only, and not the pad.


If the cam lobe touches the tappet adjusting tool, the stress may fracture the cylinder head. DO NOT ALLOW THE CAM LOBE TO CONTACT THE TAPPET ADJUSTING TOOL.

4. Carefully rotate the cam so that the pad can be removed. To avoid cam touching the adjusting tool, turn cams as follows: (view from left side of the motorcycle) Intake: Carefully rotate CLOCKWISE. Exhaust: Carefully rotate COUNTERCLOCKWISE.

5. Remove the pad from the lifter. There is a slot in the lifter. Use a small screwdriver or other blade and tweezers or a magnetic rod to remove the pad. Note the number on the pad.

6  Proper pad selection is made as follows:

Chart lookup method:

(Use appropriate chart for exhaust or intake valves, attached to this page, below.)

a.   Find number of original (installed) pad number on chart. Read down on chart.

b.   Find measured valve clearance (from step 1) on chart. Read across.

c.   At the intersection of installed pad number (down) and measured clearance (across) is a new pad number.


Intake valve, installed pad:

No. 250 (read down) Measured clearance:

0.32 mm (read across) New pad number: No. 270

(intersection of down & across)


The new pad number is to be used as a guide only. Verify the correctness of this choice in the following step(s).

7.    Install the new pad in the lifter. Install the pad with the number down.

8.    Remove tappet adjusting tool,

9.   Turn crankshaft to rotate cam several rotations. This will set the pad in the lifter.

10.   Check valve clearance (step 3). If clearance is incorrect, repeat preceding steps until proper clearance is obtained.

11.    Inspect head cover gasket. If bent or torn, replace gasket.

12.    Reinstall removed parts in reverse order.

Alternate shim calculation method:

Since all shims come in .05mm (.002") increments, you can quickly calculate the required size without a chart.

If the measured clearance is within 0.05mm (0.002") of the required clearance, then no change is needed. 

If the measured clearance greater than 0.05mm (0.002") but 0.10mm (0.004") or less different than the required clearance then the next size shim is required.

If the measured clearance greater than 0.10mm (0.004") but 0.15mm (0.006") or less different than the required clearance then the next size shim is required.

Clearances that are too small require thinner shims. Clearances that are too large require thicker shims.

Example: Required exhaust valve clearance is 0.16~0.20mm. Measured clearance is 0.12mm (gap too small). Installed shim is Y270. Required shim is one size thinner: Y265.

B. Cam Chain Adjustment

The cam chain becomes stretched with use, resulting in improper valve timing and engine noise. To prevent this, the cam chain tensioner must be adjusted regularly.

1.    Remove the timing plate cover.

2.   Slowly rotate the crankshaft counterclockwise until the "C" mark on the timing plate aligns with the stationary pointer.

3. Loosen the tensioner lock nut and then loosen the stopper bolt. This releases the cam chain tensioner with the proper tension.

1. Lock nut 2. Stopper bolt

4. Tighten the stopper bolt and lock nut.

Stopper bolt torque: 0.6 m-kg (4.3 ft-lb) Lock nut torque: 0,9 m-kg (6.5 ft-lb)

5. Reinstall the timing plate cover.

C. Ignition Timing

1. Ignition timing is checked with a timing light by observing the position of the stationary pointer and the marks stamped on the timing plate.

The timing plate is marked as follows:



... Firing range for No.1 (L.H.)



... Top Dead Center for No. 1 
(L.H.) and No. 4 (R.H.)

2.    Connect the timing light to No. 1 (L.H.) spark plug lead wire.

3.   Start the engine and keep the engine speed as specified. Use a tachometer to check the engine speed.

Specified engine speed: 1,050 r/min

4. The stationary pointer should be within the limits of "PI" on the timing plate. If it exceeds the limits or does not steady, check the timing plate for tightness and/or ignition system for damage. (See "CHAPTER 6. ELECTRICAL)


Never bend the stationary pointer.                 |

D. Air Cleaner

1. Removal

a.   Remove the seat.

b.   Remove the tool tray.

c.   Remove the air filter case cover by removing the three screws.

d. Pull out the element.

1. Air filter element

2. Cleaning method

Tap the element lightly to remove most of the dust and dirt; then blow out the remaining dirt with compressed air from the inner surface of the element. If element is damaged, replace it.

3.    Reassemble by reversing the removal procedure. Check whether the element is seated completely against the case.

4.    The air filter element should be cleaned at the specified intervals.



The engine should never be run without the air cleaner element installed; excessive piston and/or cylinder wear may result.

E. Carburetor NOTE:

The carburetors are numbered 1, 2, 3, and 4 from the left when viewed from astride the motorcycle.

1.    Idle mixture

The idle mixture is set at the factory by the use of special equipment. Not attempt should be made by the dealer to change this adjustment.

2.    Synchronization

The seat must be removed and the rear of the tank elevated to gain access to the vacuum connections and throttle adjustment screws. 


The valve clearances must be set properly before synchronizing the carburetors.

a. Remove the vacuum pipe from the carburetor manifold (No. 3 cylinder) and turn the fuel petcock to "PRI".

b. Remove the rubber caps from the No. 1, 2, and 4 carburetor manifolds.

c. Connect the each vacuum gauge hose to its proper carburetor.

1. Vacuum gauge

d.  Start the engine and allow it to warm-up for a few minutes. The warm-up is complete when engine responds normally to the throttle opening.

e.  Set the engine idle at approximately 1,050 r/min.

f.   Each gauge reading will indicate the same if the carburetors are synchronized. The No. 3 carburetor has no synchronizing screw and the other carburetors are to be synchronized to it in order, one at a time.

First, synchronize carburetor No. 1 to carburetor No. 2 by turning the No. 1 synchronizing screw until both gauges read the same.

Second, in the same way synchronize carburetor No. 4 to carburetor No. 3. Third, by adjusting No. 2 screw to watch No. 3 carburetor reading, No.1 and No.2 carburetors will both change to match No. 3 carburetor.

1. Synchronizing screws

3. Idle speed adjustment


Carburetors must be synchronized before setting final idle speed. The idle speed adjustment is made by turning only one throttle stop screw.

a.   The engine must be warmed up before setting idle speed.

b.   Set the engine idle speed by turning the throttle stop screw in (to increase engine speed) or out (to decrease engine speed).

Standard idle speed: 1,050 ± 50 r/min

1. Throttle stop screw

F. Engine Oil

1. Oil level measurement a. Place the motorcycle on the center stand. Warm up the engine for several minutes. 


Be sure the motorcycle is positioned straight up when checking the oil level; a slight tilt toward the side can produce false readings.

b. With the engine stopped, check the oil level through the level window located at the lower part of the right side crank-case cover.


Wait a few minutes until the oil level settles before checking.

c. The oil level should be maximum level. If the level is lower, add sufficient oil to raise it to the maximum level. 

2. Engine oil and oil filter replacement

a.   Start, the engine and stop it after a few minutes of warm-up.

b.  Place an oil pan under the engine and remove the oil filler cap.

c.   Remove the engine and middle gear drain plugs and drain the oil.

1. Engine drain plug

1. Middle gear drain plug

d. Remove the oil filter bolt and filter element.

1. Oil filter cover

e. Re-install the drain plugs (make sure they are tight).

Drain plug torque:


Middle gear:


m-kg (11.6 ft-lb)




f. Install the new oil filter element, new "O-ring" and filter cover, tighten the oil filter bolt.

Oil filter bolt torque: 1.5 m-kg (11.0 ft-lb)


When installing the filter cover, make sure the "O-ring" is positioned properly and insert the locating projection on it into the corresponding guides on the crankcase.

1. Proper O-ring position

g. Add oil through the oil filler hole.

Periodic oil change: 2.35 lit (2.5 US qt.)

With oil filler replacement: 2.65 lit (2.8 US qt.)

Recommended oil:

h. After replacement of the engine oil, and/ or oil filter, be sure to check for oil leakage. The oil level indicator light should go off after the oil is filled.


If the indicator light flickers or remains on, the oil level switch may be damaged. Refer to "CHAPTER 6" for corrective action.

G. Final Gear Oil

1. Oil level measurement

a.   Place the motorcycle on a level place and place it on the center stand. The engine should be cool (at atmospheric temperature).

b.   Remove the oil filler cap and check the oil level whether it is to the hole brim. If it is not up to this level, replenish oil.


Take care not to allow foreign material to enter the final gear case.

2. Gear oil replacement

a.   Place an oil pan under the final gear case.

b.   Remove the final gear oil filler cap and the drain plug, and drain the oil.

1. Final gear drain plug

c. Reinstall and tighten the final gear drain

plug. d. Fill the gear case to the specified level.

Oil capacity: 0.20 lit (0.21 US qt.) Recommended oil: SAE 80 API "GL-4" Hypoid gear oil

If desired, an SAE 80W/90 hypoid gear oil may be used for all conditions.

e. Reinstall the filler cap securely.

H. Compression Pressure Measurement

Insufficient compression pressure will result in performance loss and may indicate leaking valves or worn or damaged piston rings. Procedure:

1.   Make sure the valve clearance is correct.

2.    Remove the headlight fuse from the fuse box.

3.   Warm up the engine 2 ~ 3 minutes. Stop the engine.

4.    Remove the all spark plugs.

5.    Install a compression check gauge.

6.   Turn over the engine with the electric starter (make sure the battery is fully charged) with the throttle wide open until the pressure indicated on the gauge does not increase further.

Compression pressure (at sea level):

Standard.......11 kg/cm2 (156 psi)

Minimum.......9 kg/cm2 (128 psi)

Maximum......12 kg/cm2 (171 psi)


When cranking the engine, ground the removal spark plug wires to prevent sparking.

1. Compression gauge

7.    If the pressure is too low, squirt a few drops of oil into the cylinder being measures. Measure compression again. If there is a higher reading than before (without oil), the piston rings may be worn or damaged. If the pressure remains the same after measuring with the oil, either or both the rings and valves may be the cause.

8.    Check each cylinder. Compression pressure should not vary more than specified value from one cylinder to any other cylinder.

Difference in gauge reading: Less than 1 kg/cm2(14 psi)

I. Clutch Adjustment

Free play adjustment

a.   Loosen either the handle lever adjuster lock nut or the cable length adjuster lock nut.

b.  Turn the cable length adjuster either in or out until proper lever free play is achieved.

1. Lock nut 2. Adjuster a. 2~3 mm (0.08~0.12 in)

1. Lock nut 2. Adjuster

Chassis Maintenance


A. Fuel Petcock

If the fuel petcock is leaking or excessively contaminated, it should be removed from the fuel tank and inspected.

1.    Remove the fuel tank and position it so that fuel will not spill when the petcock is removed.

2.    Remove the petcock and inspect the filter screen. Replace the filter if seriously contaminated.

3.    Remove the screws on the front and rear of the petcock and remove the plate, gaskets, lever, and diaphragm.

4.    Inspect all components and replace any that are damaged. If the diaphragm is in any way damaged, or the petcock body gasket surfaces scratched or corroded, the petcock assembly must be replaced. If there is abrasive damage to any component, the fuel tank must be drained and flushed.

5.    Reassemble the petcock and install it on the fuel tank.

B. Front and Rear Brake

1. Brake adjustment

a. Front brake lever free play adjustment. The brake can be adjusted by simply adjusting the free play of the brake lever. The piston in the caliper moves forward as the brake pad wears out, automatically adjusting the clearance between the brake pads and brake disc.


Proper lever free play is essential to avoid excessive brake drag.

1. Adjuster 2. Lock nut a. 5~8 mm (0-2

1)   Loosen the adjuster lock nut on the brake lever.

2)  Turn the adjuster so that the brake lever movement at the lever end is 5- 8 mm (0.2 ~ 0.3 in) before the adjuster contacts the master cylinder piston.

3)  After adjusting, tighten the lock nut. b. Rear brake pedal height adjustment

1)   Loosen the adjuster lock nut (for pedal height).

2)   By turning the adjuster bolt clockwise or counterclockwise, adjust the brake pedal position so that its top end is approximately 20 mm (0.78 in) below the footrest top end.

3)  Secure the adjuster lock nut.


After adjusting the pedal height, the brake pedal free play should be adjusted.

c. Rear brake pedal free play adjustment

1. Adjuster bolt

3. Footrest

(for pedal height)

4. Pedal height 20 mm [0.8 in)

2. Lock nut

5. Free play 20~ 30 mm (0.8-^ 1.2 in)

Turn the adjuster on the brake rod clockwise or counterclockwise to provide the brake pedal end with a free play of 20 — 30 mm (0.8-1.2 in).


Check to see whether or not the brake light operates correctly after adjusting.

2. Front brake pad and rear brake shoe check

A. Front Brake Pad Check

To check pad wear, open the wear indicator cap. If any pad is worn to the red line, replace both pads in the caliper.

1. Wear indicator

b. Rear brake shoe

To check, see the wear indicator position while depressing the brake pedal. If the indicator reaches to the wear limit line, replace the shoes.

1. Wear limit 2. Wear indicator

3. Brake fluid

Insufficient brake fluid may allow air to enter the brake system, possibly causing the brake to become ineffective. Check the brake fluid level and replenish when necessary observing these precautions:

1. Lower level

a.   Use only the designated quality brake fluid; otherwise, the rubber seals may deteriorate, causing leakage and poor brake performance.

Recommended brake fluid: DOT #3

b.   Refill with the same type and brand of brake fluid; mixing fluids may result in a harmful chemical reaction and lead to poor performance.

c.   Be careful that water or other contamination does not enter the master cylinder when refilling. Water will significantly lower the boiling point and may result in vapor lock.

d.   Brake fluid may erode painted surfaces or plastic parts. Always clean up spilled fluid immediately.

C. Tubeless Tires and Aluminum Wheels

This motorcycle is equipped with aluminum wheels designed to be compatible with either tube or tubeless tires. Tubeless tires are installed as standard equipment.


Do not attempt to use tubeless tires on a wheel designed for use only with tube-type tires. Tire failure and personal injury may results from sudden deflation. Tube-type Wheel — Tube-type tires only Tubeless-type Wheel — Tube-type or

Tubeless tires When using tube-type tires, be sure to install the proper tube also.

To insure maximum performance, long service, and safe operation, note the following precautions:

1.   Check tire pressure, before riding, adjust as necessary.

2.    Before operation, always check the tire surfaces for wear and/or damage; look for cracks, glass, nails, metal fragments, stones, etc. Correct any such hazard before riding.

3.   Always inspect the aluminum wheels before a ride. Place the motorcycle on the center stand and check for cracks, bends or warpage of the wheels. Do not attempt even small repairs to the wheel. If a wheel is deformed or cracked, it must be replaced.

4.   Tires and wheels should be balanced whenever either one is changed or replaced. Failure to have a wheel assembly balanced can result in poor performance, adverse handling characteristics, and shortened tire life.

5.   After installing a tire, ride conservatively to allow the tire to seat itself on the rim properly. Failure to allow proper seating may cause tire failure resulting in damage to the motorcycle and injury to the rider.

6.   After repairing or replacing a tire, check to be sure the valve stem lock nut is securely fastened. If not, torque it as specified.

Tightening torque:

0.15 m-kg (1.1 ft-lb)

D. Front Fork Oil Change

1.    Raise the motorcycle or remove the front wheel so that there is no weight on the front end of the motorcycle. Remove the handlebar if necessary.

2.    Remove the rubber cap from the top of each fork.

3.    The spring seat and fork spring are retained by a stopper ring (spring wire circlip). It is necessary to depress the spring seat and fork spring to remove the stopper ring. Remove the stopper ring by carefully prying out one end with a small screwdriver.

4.    Place an open container under each drain hole. Remove the drain screw from each outer tube.

1. Drain screw

WARNING: Do not allow oil to contact the disc brake components. If any oil should contact the brake components it must be removed before the motorcycle is operated. Oil will cause diminished braking capacity and will damage the rubber components of the brake assembly.

5.    When most of the oil has drained, slowly raise and lower the outer tubes to pump out the remaining oil. It may be necessary to remove the spring seat and top spring to keep them from falling out when raising fork tubes.

6.    Inspect the drain screw gasket. Replace if damaged. Reinstall the drain screw.

7.    Pour the specified amount of oil into the fork inner tube.

Front fork oil (each fork): 236 cc (7.98 US oz)

Recommended oil: YAMAHA FORK OIL 10Wt or equivalent.

1. Cap
2.  Stopper ring
3.  Spring seat
4.  O-ring

8.    After filling, slowly pump the forks up and down to distribute the oil.

9.    Inspect the "O-ring" on the spring seat. Replace "O-ring" if damaged.

10. Reinstall the spring seat, stopper ring and rubber cap.


Always use a new stopper ring (spring wire circlip).

C. Front Wheel Removal

1.    Place the motorcycle on the center stand.

2.    Remove the front fender securing bolts and remove the fender.

3.    Remove the cotter pin and wheel axte nut.

4.    Loosen the left and right pinch bolts securing the axle.

1. Pinch bolt

5.    Remove the axle shaft. In this case, make sure the motorcycle is properly supported.

NOTE: Do not depress the brake lever when the wheel is off the motorcycle as the brake pads will be forced to shut.

6.    Lower the wheel until the brake discs come off the calipers. Turn the calipers outward so they do not obstruct the wheel and remove the wheel.

E. Rear Shock Absorber


If the spring seat is raised, the spring becomes stiffer and if lowered, it becomes softer.

Standard position................A

A. position.................Softest

E. position................ Stiffest

F. Steering Head Adjustment

The steering assembly should be checked periodically for looseness.

1.    Raise the front end of the motorcycle so that there is no weight on the front wheel.

2.    Grasp the bottom of the forks and gently rock the fork assembly backward and forward, checking for looseness in the steering assembly bearings.

3.    If there is looseness in the steering head, loosen the steering stem and front fork pinch bolts and steering fitting bolt.

4.    Use a steering nut wrench to loosen top steering fitting nut. The top nut serves as a lock nut.

5.   Tighten the lower steering fitting nut until the steering head is tight, but does not bind when forks are turned.

6.    Retighten the top steering fitting nut, steering fitting bolt and steering stem and front fork pinch bolts, in that order.

7.    Recheck steering adjustment to make sure there is no binding when the forks are moved from lock to lock. If necessary, repeat adjustment procedure.

G. Cable Inspection and Lubrication


Damage to the outer housing of the various cables, may cause corrosion and often free movement will be obstructed. An unsafe condition may result so replace such cables as soon as possible.

1. If the inner cables do not operate smoothly, lubricate or replace them.

Recommended lubricant:

Yamaha Chain and Cable Lube or SAE 10W/30 motor oil

H. Throttle Cable and Grip Lubrication

The throttle twist grip assembly should be greased when the cable is lubricated, since the grip must be removed to get at the end of the throttle cable. Two screws clamp the throttle housing to the handlebar. Once these two are removed, the end of the cable can be held high to pour in several drops of lubricant. With the throttle grip disassembled, coat the metal surface of the grip assembly with a suitable all-purpose grease to cut down friction.

I. Rear Arm Pivot Bearings

The swing arm must pivot freely on its bearings but not have any excess play. Check and adjust pivot bearings if necessary. (Refer to CHAPTER 5. SWING ARM).

J. Brake and Change Pedals/Brake and Clutch Levers

Lubricate the pivoting parts of each lever and pedal.

Recommended lubricant: Yamaha Chain and Cable Lube or SAE 10W/30 motor oil

K.Center and Side Stand Pivots

Lubricate the center and side stands at their pivot points.

Recommended lubricants: Yamaha Chain and Cable Lube or SAE 10W/30 motor oil

Electrical Maintenance


A. Battery

1. The fluid level should be between the upper and lower level marks. Use only distilled water if refilling is necessary.


Normal tap water contains minerals which are harmful to a battery; therefore, refill only with distilled water.

2. Always make sure the connections are correct when installing the battery. Make sure the breather pipe is properly connected, properly routed, and is not damaged or obstructed.


The battery must be charged before using to insure maximum performance. Failure to properly charge the battery before first use, or low electrolyte level will cause premature failure of the battery. Charging current: 1.2 amps/10 hrs or until the specific gravity reaches 1.280 at 20°C (68°F)


Battery electrolyte is poisonous and dangerous, causing severe burns, etc. Contains sulfuric acid. Avoid contact with skin, eyes or clothing. Antidote: EXTERNAL-Flush with water.

INTERNAL—Drink large quantities of water or milk. Follow with milk of magnesia, beaten egg or vegetable oil. Call physician immediately.

Eyes: Flush with water for 15 minutes and get prompt medical attention. Batteries produce explosive gasive gases. Keep sparks, flame, cigarettes, etc. away. Ventilate when charging or using in closed space. Always shield eyes when working near batteries. KEEP OUT OF REACH OF CHILDREN.

B. Spark Plug

1. Check the electrode condition and wear, insulator color and electrode gap.

2.    Use a wire gauge for measuring the plug gap.

3.    If the electrodes become too worn, replace the spark plug.

4.    When installing the plug, always clean the gasket surface. Wipe off any grime that might be present on the surface of the spark plug, and torque the spark plug properly.

Standard spark plug:

BP7ES (NGK) or W22EP (ND) Spark plug gap: 0.7 ~ 0.8 mm (0.028 ~ 0.032 in)

Spark plug tightening torque: 2.0 m-kg (14.5 ft-lb)

C. Headlight

1. Headlight bulb replacement a. Remove the 2 screws holding the light unit assembly to the headlight body.

b. Disconnect the lead wires and remove the light unit assembly.

c. Remove the top and bottom fitting screws and the horizontal adjusting screw. Remove the light unit assembly from the headlight rim.

d. Remove the sealed beam unit holding screws. Remove the unit retaining ring and the defective unit.

e.   Slip a new sealed beam unit into position and secure it with the retaining ring and install it into the headlight rim.

f.   Reinstall the light unit assembly to the headlight body. Adjust the headlight beam.

2. Headlight beam adjustment a. Horizontal adjustment

To adjust the beam to the right, turn the

adjusting screw clockwise.

To adjust the beam to the left, turn the

screw counterclockwise.

b. Vertical adjustment:

Loosen the adjusting screw under the headlight body. Adjust vertically by moving the headlight body. When proper adjustment is determined, retighten the adjusting screw.

D. Fuse

The fuse block is located under the seat. If any fuse is blown, turn off the ignition switch and the switch in the circuit in question and install a new fuse of proper amperage. Then turn on the switches, and see if the electrical device operates. If the fuse immediately blows again, check the circuit in question (refer to "CHAPTER 6. ELECTRICAL").


Do not use fuses of a higher amperage rating than those recommended. Substitution of a fuse of improper rating can cause extensive electrical system damage and possible fire.



Engine Removal


NOTE: It is not necessary to remove the engine in order to remove the cylinder head, cylinder, or pistons.

A.   Preparation for Removal

1.    All dirt, mud, dust and foreign material should be thoroughly removed from the exterior of the engine before removal and disassembly. This will help keep harmful foreign material from the engine oil.

2.    Before the engine removal and disassembly, be sure that you have the proper tools and cleaning equipment so that you can perform a clean and efficient job.

3.    During disassembly of the engine, clean and place all of the parts in trays in order of disassembly. This will speed up assembly time and help insure correct reinstallation of all the engine parts.

4.    Place the motorcycle on its center stand. Start the engine and allow it to warm up. Stop the engine and drain the engine and middle gear oil.

5.    Remove the oil filter element from the crankcase.

6.    Remove the left and right side covers.

B.   Fuel Tank

1.    Turn the fuel cock to "ON".

2.    Open the seat and remove the fuel tank securing clamp and retainer. Lift the rear end of the fuel tank and disconnect the fuel pipe and vacuum pipe from the cock.

1. Clip 2. Retainer

3. Remove the tool tray.

C . Brake Pedal and Exhaust Pipe

1.    Remove the rear brake pedal.

2.    Remove the exhaust pipe holding nuts from the cylinder head.

3.    Loosen the clamp bolts securing the exhaust pipes to the right and left mufflers. Remove the exhaust pipes.

4. Remove the bolts holding the muffler bracket to the crankcase.

D. Battery Case

1. Remove the negative battery cable from the battery terminal then remove the positive battery plate. Remove the battery.

1. Positive battery plate

2. Remove the starter motor lead wire from the starter relay and disconnect the relay leads form the wire harness.

1.  Starter motor lead wire `2. Starter relay

3. Remove the battery case holding bolts and remove the battery case with the starter relay assembly.

E. Air Cleaner Case

1.    Remove the ignitor unit mounting board securing screw and disconnect all connectors. Remove the board assembly.

2.    Remove the clamps holding the carburetors to the air cleaner case and intake manifolds.         Remove the crankcase ventilation hose at the air cleaner case.

1. Crankcase ventilation hose

3. Remove the bolts holding the air cleaner case to the frame (left and upper)

1. Engine ground wire

4.    Remove the air cleaner joint rubbers.

5.    Remove the starter (CHOKE) and clutch cables from the carburetor assembly.

6.    Pull the carburetor assembly to the rear.

1. Starter (CHOKE) cable    2. Clutch cable

7. Disconnect the throttle cable from the carburetor throttle lever and remove the carburetor assembly to the right.

1. Throttle cable

F. Wiring and Cables

1.    Disconnect the clutch cable at the crank-case side.

2.    Remove the spark plug lead wires and the tachometer cable.

3. Disconnect the pick-up coil and A.C.G. lead wire couplers.

Position the disconnected wires so they will not be damaged during engine removal.

CAUTION: The A.C.G. lead, starter cable, and pick-up lead are clamped at the upper cross tube of the frame. Do not forget to remove this clamp before removing the engine.

G. Drive Shaft Joint

1.    Remove the coil spring holding the rubber boot.

2.    Pull the rubber boot from the drive shaft coupling to expose the joint bolts.

3.    Remove the joint bolts on the drive shaft coupling.

I. Engine Removal

1. Remove the front engine mounting bolts and nuts. Remove the brackets.

1 Front engine mounting bolts

2. Remove the rear engine mounting bolts and right and left footrests.

3. Slide the engine forward slightly and remove the engine to the right.

NOTE: Position a box or other support to the right side of the motorcycle for the assistance when removing the engine.

Cylinder Head Removal


A. Cylinder Head and Cylinder

1.    Remove the cylinder head cover.

2.    Remove the left crankcase cover (pickup coil cover).

3.    Remove the cam chain tensioner.

4. Use a 19 mm wrench on the timing plate flats to rotate the crankshaft counterclockwise until the engine is at T.D.C.

Never use an alien wrench to rotate the crankshaft. Always use the 19 mm flats provided on the timing plate to rotate this engine.

5. Remove the four cam sprocket bolts.

6. Slip each sprocket off its mounting boss on the cam.


From this point on, do not rotate the cam shaft or valve damage may occur. On this, it is not necessary to break the cam chain. However, it can be broken if so desired. It is easier to disassemble the engine without separating the chain.

7. Remove the cam chain guide.

1, Cam chain guide

8. Remove the cam caps. Note the location of the cam caps. The caps for the intake cam shaft are identified 1-1 through I-3. The exhaust cam caps are identified E-1 through E-3. Directional arrows are cast on each cap and point toward the clutch side.

9. Fasten safety wire to the cam chain to prevent its falling into the crankcase cavity.

Slide the cams and sprockets from under the chain and remove the cams and sprockets.

10. Remove the front cam chain guide.

1. Front cam chain guide

11.    Remove the spark plugs.

12.    Remove the cylinder head bolts and nuts in the numerical order as shown. Start by loosening each nut 1/2 turn until all of the nuts are loose. Remove the cylinder head.


Cylinder and Cylinder Head Disassembly

13. Remove the front cylinder holding nut and remove the cylinder assembly. It may be necessary to tap the cylinder lightly to loosen it from the base gasket.

14. Remove the rear cam chain guide by loosening the holding bolt.

1. Holding bolt 2. Rear cam chain guide

B. Cylinder Head Disassembly

1. Remove the valve lifters and pads. Be careful not to scratch the lifter bodies or lifter bores in the cylinder head. Be very careful to identify each lifters position so that it may be returned to its original place.

1. Valve filter 2. Adjusting pad

2. Mount the valve spring compressor on the head and depress each valve spring. Take out the retainer and valve spring with tweezers.

1. Valve spring compressor

3. Remove valves.


Deburr any deformed valve stem end. Use an oil stone to smooth the stem end. This will help prevent damage to the valve guide during valve removal.

4. Use a small box to hold the parts and identify the original position of each lifter and valve. Be very careful not to mix the location of these components.


Piston, Pickup Coil, Shifter, Starter, Generator and Clutch Removal

C. Piston

1. Mark each piston to aid in reassembly.

2.   Place a clean towel or rag into the crank-case to keep circlips and material from falling into the engine.

3.    Remove piston pin clips, piston pins, and pistons.

D. Pick-up Coil Assembly

1. Remove the alien bolt that holds the timing plate.

2. Remove the pick-up coil securing screws and remove the pick-up coil assembly.

E. Shifter

1.    Remove the change pedal.

2.    Remove the left crankcase cover.

3. Remove the shift lever assembly and shift shaft assembly.

1. Shift lever assembly 2. Shift shaft assembly

4. Remove the middle gear case oil level maintaining plug.

F. Starter Motor and Generator

1. Remove the starter motor securing bolts and remove the motor assembly.

2. Remove the generator cover and stator coil assembly.


3. Install the rotor holding tool (special tool) on the rotor as shown and remove the rotor holding bolt.

1. Rotor holding tool

4. Invert the holding tool as shown and insert the rotor puller adapter (special tool) into the rotor shaft and screw in the rotor puller (special tool). Remove the rotor.

1. Rotor puller adapter

G. Clutch

1. Remove right crankcase cover.

2. Release the tension evenly on the 6 mm bolts and remove the clutch pressure plate and clutch springs.

3.    Remove the friction plates and clutch plates.

4.   Straighten the lock washer tab. Use the clutch boss holder (special tool) to hold the clutch boss and remove the lock nut and lock washer.

1. Clutch boss holder

5. Remove the clutch boss and spacer.

6. Screw in a suitable length of 6 mm bolt into the one of the threaded holes on the collar and pull out the collar and needle bearing from the primary driven gear.

1. Collar

7. Remove the primary driven gear assembly and oil pump drive sprocket.

Oil Pump and Middle Gear Disassembly

H. Oil Pump Removal and Disassembly

1. Remove the strainer cover. Note the wire harness clip position.

2. Remove the oil pump securing bolts and remove the sprocket cover and oil pump assembly.


Do not attempt to remove the strainer screen as it is permanently fitted onto the pump housing. If the pump housing and/or any parts of the pump are damaged, the pump assembly must be replaced with a new one.

3. Remove the oil pump driven sprocket.

4, Remove the oil pump cover and rotor assembly.

5. Remove the pressure relief valve spring and plunger.

I. Middle Gear

1. Remove the middle driven gear housing holding bolts.

2.    Remove the middle driven gear housing assembly and shims.


If it is difficult to remove housing assembly, loosen the two crankcase bolts located near the middle driven gear housing.

3. Remove "TORX" screws holding the middle drive gear assembly.

4. Remove the bearing retainers.

Upper Crankcase Disassembly

J. Crankcase Disassembly

1. Remove the upper crankcase bolts, starting the highest numbered bolt. Turn over the engine and remove the lower crankcase bolts,





2. Separate the lower case from the engine. Use a soft rubber hammer to carefully separate the crankcase.

K. Upper Crankcase

1. Remove the middle drive gear and damper assembly.

2. Remove the transmission main shaft assembly.

3. Remove the A.C.G. shaft cover.

4, Remove the oil spray nozzle.

5. Carefully remove the A.C.G. shaft from the gear.

6. Remove the gear from the chain.

7. Straighten the lock washer tube and remove the bolt securing the starter idle gear shaft. Remove the shaft and starter idle gear.

Lower Crankcase Disassembly

L. Lower Crankcase

1.    Remove the dowel pin and "O-ring".

2.    Remove the shift fork guide bar and shift forks. The shift forks are identified by numbers cast on their sides.

3.    Remove the bolt securing the shift cam locating pin and remove the stopper plate and locating pin.

4.    Remove the neutral switch.

1. Shift cam locating pin 2. Neutral switch

5.   Pull out the shift cam.

6.    Remove the driven shaft bearing cover holding screws and remove the bearing cover.

7. Remove the bearing and 5th wheel gear from the driven shaft and pull out the driven shaft assembly.

1. 5th wheel gear

Cylinder Head and Valves -- Inspection & Repair


A.   Cylinder Head Cover

Place head cover on a surface plate. There should be no warpage. Correct by re-surfacing as follows:

Place #400 or #600 grit wet sandpaper on surface plate and re-surface head cover using a figure-eight sanding pattern. Rotate head cover several times to avoid removing too much material from one side.

B.   Cylinder Head

1. Using a rounded scraper, remove carbon deposits from combustion chamber. Take care to avoid damaging spark plug threads and valve seats. Do not use a sharp instrument. Avoid scratching the aluminum.

2.    Check the cylinder head warpage with a straight edge as shown.

The warpage should not exceed the specified limit, if necessary resurface. If the warpage exceeds allowable limit, the cylinder head should be replaced with a new one.

Cylinder head warpage:

less than 0.05 mm (0.002 in) Allowable limit: 0.25 mm (0.010 in)

C. Valve, Valve Guide, and Valve Seat

1. Check the valve face and the stem end for wear. If the valve face and/or the stem end are pitted or worn, regrind the valve with a valve refacer. Replace the valve if any dimension exceeds the specifications in the illustration.

2. Valve stem wear must be measured and then combined with valve guide measurements to guide clearance. This clearance must be within tolerances. If it exceeds the maximum limit, then replace either or both valve and guide, as necessary.

Valve Stem Clearance



0.010 — 0.037 mm (0.0004-0.0015 in)

0.10 mm (0.004 in)


0.025-0.052 mm (0.0010-0.0020 in)

0.12 mm (0.005 in)


3.    Valve stem end

Inspect the end of the valve stem. If the end appears to be "mushroomed" or has a larger diameter than the rest of the stem, the valve, valve guide, and oil seal should be replaced.

4.   Turn valve on "V" blocks and measure the amount of stem runout with a dial gauge. If it exceeds the maximum limit, replace the valve.

Maximum valve stem runout: 0.03 mm (0.0012 in)

5. Valve guide and valve oil seal replacement If oil leaks into the cylinder through a valve due to a worn valve guide, or if a valve is replaced, the valve guide should also be replaced.


The valve oil seal should be replaced whenever a valve is removed or replaced.

a. Measure valve guide inside diameter with a small bore gauge. If it exceeds the limit, replace with an oversize valve guide.

Guide diameter (I.D.):

Limit: 7.10 mm (0.280 in)

b.  To ease guide removal and reinstallation, and to maintain the correct interference fit, heat the head to 100t (212°F). Use an oven to avoid any possibility of head warpage due to uneven heating.

c.   Use the appropriate shouldered punch (special tool) to drive the old guide out and drive the new guide in.


When a valve guide is replaced, the O-ring should also be replaced.

1. Valve guide remover

2. Valve guide installer

d. After installing the valve guide, use the 7 mm reamer (special tool) to obtain the proper valve guide to valve stem clearance.

e. After installing the valve guide in the cylinder head, the valve seat must be recut. The valve should be lapped to the new seat.

6. Grinding the Valve Seat

a. The valve seat is subject to severe wear. Whenever the valve is replaced or the valve face is re-surfaced (see caution) the valve seat should be re-surfaced at a 45° angle. If a new valve guide has been installed the valve seat must be recut to guarantee complete sealing between the valve face and seat.


If the valve seat is obviously pitted or worn, it should be cleaned with a valve seat cutter. Use the 45° cutter, and when twisting the cutter, keep an even downward pressure to prevent chatter marks.

If cutting section "A" of the valve seat, use 30° cutter. If cutting section "B", use the 45° cutter. If cutting section "C" use 60° cutter. b. Measure valve seat width. Apply mechanic's bluing dye (such as Dykem) to the valve face and valve seat, apply a very small amount of fine grinding compound around the surface of the valve face insert the valve into position, and spin the valve quickly back and forth. Lift the valve, clean off all grinding compound, and check valve seat width. The valve seat and valve face will have removed bluing wherever they contacted each other. Measure the seat width with vernier calipers. It should measure approximately 1.1 mm (0.0433 in). Also, the seat should be uniform in contact area. If valve seat width varies, or if pits still exist, further cutting will be necessary. Remove just enough material to achieve a satisfactory seat.

Standard Width

Wear Limit

Seat width

1.0 ±0.1 mm (0.0394 ± 0.0039in)

2.0 mm (0.080 in)

a. Seat width

c. If the valve seat is uniform around the perimeter of the valve face, but is too wide or not centered on the valve face, it must be altered. Use either the 30°, 45° or 60° cutters to correct the improper

seat location in the manner described below:

1) If the valve face shows that the valve seat is centered on the valve face, but too wide, then lightly use both the 30° and the 60° cutters to reduce the seat width to 1.1 mm (0.0433 in).

1. Valve seat cutter

2)   If the seat shows to be in the middle of the valve face, but too narrow, use the 45°cutter until the width equals 1.1 mm (0.0433 in).

3)   If the seat is too narrow and right up near the valve margin, then first use the 30° cutter and then the 45° cutter to get the correct seat width.

4)   If the seat is too narrow and down near the bottom edge of the valve face, then first use the 60° cutter and then the 45° cutter.

7. Lapping the valve/valve seat assembly a. The valve/valve seat assembly should be lapped if neither the seat nor the valve face are severely worn.

b. Apply a small amount of coarse lapping compound to valve face. Insert the valve into the head. Rotate the valve until the valve and valve seat are evenly polished. Clean off the coarse compound, then follow the same procedure with fine compound.

Continue lapping until the valve face shows a complete and smooth surface all the way around. Clean off the compound material. Apply bluing dye to the valve face and seat and rotate the valve face for full seat contact which is indicated by a grey surface all around the valve face where the bluing has been rubbed away.

c. Valve leakage check

After all work has been performed on the valve and valve seat, and all head parts have been assembled, check for proper valve/valve seat sealing by pouring solvent into each of the intake ports, then the exhaust ports. There should be no leakage past the seat. If fluid leaks, disassemble and continue to lap with fine lapping compound. Clean all parts thoroughly, reassemble and check again with solvent. Repeat this procedure as often as necessary to obtain a satisfactory seal.


Valve Springs and Lifters, Camshafts, Chain and Guides -- Inspection and Repair

D. Valve Spring and Lifters

1. Checking the valve springs

a.   This engine uses two springs of different sizes to prevent valve float or surging. The valve spring specifications show the basic value characteristics.

b.   Even though the spring is constructed of durable spring steel, it gradually loses

some of it's tension. This is evidenced by a gradual shortening of free length. Use a vernier caliper to measure spring free length. If the free length of any spring has decreased more than 2 mm (0.080 in) from its specification replace it.

c. Another symptom of a fatigued spring is insufficient spring pressure when compressed. This can be checked using a valve spring compression rate gauge. Test each spring individually. Place it in the gauge and compress the spring first to the specified compressed length with the valve closed (all spring specifications can be found in the previous section, Valve Spring), then to the length with the valve open. Note the poundage indicated on the scale at each setting. Use this procedure with the outer springs, then the inner springs.


All valve springs must be installed with larger pitch upward as shown.

Valve Spring Specifications




Free length

39.5 mm (1.55 in)

35.9 mm (1.413 in)

Installed length (valve closed)

34.0 mm (1.339 in)

31.0 mm (1.220 in)

Installed pressure

19.1 kg (42.1 lb)

9.0 kg (19.8 1b)

Allowable tilt from vertical


2. Valve lifter

a. Check each valve lifter for scratches or other damage. If the lifter is damaged in any way, the cylinder head surface in which it rides is probably also damaged. If the damage is severe, it may be necessary to replace both the lifter and the cylinder head.


For proper valve lifter-to-head clearance, always install lifters on their original valves.

E. Camshafts, Cam chain and Cam Sprockets

1. Camshaft

a.   The cam lobe metal surface may have a blue discoloration due to excessive friction. The metal surface could also start to flake off or become pitted.

b.   If any of the above wear conditions are readily visible, the camshaft should be replaced.

c.   Even though the cam lobe surface appears to be in satisfactory condition, the lobes should be measured with a micrometer. Cam lobe wear can occur without scarring the surface. If this wear exceeds a pre-determined amount, valve timing and lift are affected. Replace the camshaft if wear exceeds the limits.

d.   Install the camshaft on the cylinder head. Place a strip of Plastigage between camshaft and camshaft cap as illustrated (lengthwise along camshaft). Tighten the nuts with specified torque. Remove the camshaft cap and determine the clearance by measuring the width of the flattened Plastigage.

Cap nut tightening torque: 1.0m-kg(7.2ft-lb)

1. Plastigage


Do not turn camshaft when measuring clearance with Plastigage.

Camshaft-to-cap clearance:


0.020-0.054 mm


(0.0008- 0.0021 in)


0.160 mm (0.006 in)

If the camshaft-to-cap clearance exceeds specification, measure camshaft bearing surface diameter.

Bearing surface diameter:


24.967-24.980 mm


(0.9830-0.9835 in)

1) If camshaft diameter is less than specification, causing excessive clearance, replace camshaft.

2)  If camshaft is within specification and camshaft-to-cap clearance is excessive, replace cylinder head.

2.    Cam chain

Except in cases of oil starvation, the cam chain wears very little. If the cam chain has stretched excessively and it is difficult to keep the proper cam chain tension, the chain should be replaced.

3.    Cam sprockets

Check cam sprockets for obvious wear.

4, Cam chain dampers and tensioner

Inspect the top cam chain damper (stopper guide) and two (2) vertical (slipper-type) dampers for excessive wear. Any that shows excessive wear should be replaced. Worn dampers may indicate an improperly adjusted or worn-out cam chain.

Cylinder and Piston -- Inspection and Repair

F. Cylinder

1.    Inspect the cylinder walls for scratches. If vertical scratches are evident, the cylinder wall should be rebored or the cylinder should be replaced.

2.   Measure cylinder wall wear as shown. If wear is excessive, compression pressure will decrease. Rebore the cylinder wall and replace the piston and piston rings. Cylinder wear should be measured at three depths with a cylinder bore gauge. (See illustration.)


Wear Limit

Cylinder bore

63.00 mm (2.480 in)

63.10 mm (2.484 in)

Cylinder taper

0.05 mm (0.002 in)

Cylinder out-of-round

0.01 mm (0.0004 in)

If the cylinder wall is worn more than the wear limit, it should be rebored.

G. Piston and Piston Rings

1. Piston

a. Measure the outside diameter of the piston at the piston skirt. Measurement should be made at a point 7.5 mm (0.3 in) above the bottom edge of the piston. Place the micrometer at right angles to the piston pin.


63.00 mm (2.480 in)

Oversize 1

63.25 mm (2.490 in)

Oversize 2

63.50 mm (2.500 in)

Oversize 3

63.75 mm (2.510 in)

Oversize 4

64.00 mm (2.520 in)

a. 7.5 mm (0.3 in)

b. Determine piston clearance as follows:

Minimum bore measurement - Maximum piston measurement = Piston clearance


63.0 mm (2.4803 in) - 62.96 mm (2.4787 in) = 0.04 mm (0.0016 in)

Piston clearance

Piston clearance:
Standard: 0.030~ 0.050 mm (0.0012~ 0.0020 in)
Service limit: 0.1 mm (0.0039 in)

c. Piston ring/ring groove fit must have correct clearance. If the piston and ring have already been used, the ring must be removed and the ring groove cleaned of carbon. The ring should then be reinstalled. Use a feeler gauge to measure the gap between the ring and the land.

Side clearance


0.03- 0.07 mm (0.0012- 0.0028 in)


0.02-0.06 mm (0.0008- 0.0024 in)

1. Feeler gauge

2. Piston ring

a. The oversize top and middle ring sizes are stamped on top of the ring.

Oversize 1

0.25 mm (0.0098 in)

Oversize 2

0.50 mm (0.0197 in)

Oversize 3

0.75 mm (0.0295 in)

Oversize 4

1.00 mm (0.0394 in)

b. The expander spacer of the bottom ring (oil control ring) is color-coded to identify sizes.

The color mark is painted on the expander spacer.



Oversize 1


Oversize 2


Oversize 3


Oversize 4


c. Push the ring into the bore and check end gap clearance with a feeler gauge.

The end gap on the expander spacer of the oil control ring is unmeasurable. If the oil control ring rails show excessive gap, all three components should be replaced.




Top/2nd ring

0.15 — 0.35 mm (0.006- 0.014 in)

1.0 mm (0.039 in)

Oil control (Rails)

0.3-0.9 mm (0.012-0.035 in)

1.5 mm (0.059 in)

H. Piston Pin

1.    Apply a light film of oil to pin. Install in connecting rod small end. Check for play. There should be no noticeable vertical play. If play exists, check connecting rod small end for wear. Replace pin and connecting rod as required.

2.    The piston pin should have no noticeable free play in piston. If the piston pin is loose, replace the pin and/or the piston.


Crankshaft, Con rods and Bearings -- Inspection and Repair

I. Crankshaft

1. Crankshaft run-out

Support the crankshaft at both ends on V-blocks. Measure the amount of crankshaft run-out on the main bearing journals with a dial gauge while rotating crankshaft.

Run-out limit: 0.040 mm (0.0016 in!

If run-out exceeds limit, replace crankshaft.

2. Inspection of bearings

Check the bearings. If the inner or outer surface is burned, flaked, rough, scratched or worn, the bearings should be replaced.

replaced. 3. Measuring main bearing oil clearance

a.   Clean all crankshaft and crankcase journal surfaces.

b.  Place upper crankcase half upside-down on a bench. Install bearing inserts into top crankcase.

c.   Install crankshaft into upper crankcase.

d.  Place Plastigage on crankshaft journal surface to be inspected.


Do not move crankshaft until clearance check has been completed.

e.   Install bearings into bottom crankcase. Carefully, place lower crankcase onto upper crankcase.

f.   Install crankcase holding bolts 1 through 10. Tighten to full torque in torque sequence cast on crankcase.

Crankcase torque (8 mm bolt): 2.4 m-kg (17.5 ft-lb)

g.   Remove bolts in reverse assembly order (10,9,8... etc.)

h. Carefully remove lower crankcase. Measure width of Plastigage on crankshaft journals to determine clearance.

Main bearing oil clearance: 0.040 - 0.064 mm (0.0016-0.0025 in)

1. Plastigage

4. Crankshaft main bearing selection a. Numbers used to indicate crankshaft journal sizes are stamped on the L.H. crank web. The first five (5) are main bearing journal numbers, starting with the left journal. The four (4) rod bearing journal numbers follow in the same sequence.

The upper crankcase half is numbered 4, 5, or 6 as shown.

1. Main bearing numbers

b. The connecting rods are numbered 4 or 5. The numbers for rods are stamped with ink on the rod itself.

1. Connecting rod size number

c. The proper bearing selection is made by subtracting the crankshaft journal number from the crankcase or rod size number. Use the color code to choose the proper bearing.


Rod No. (Minus) Journal No. = Bearing No. 5-2 = 3 No. 3 bearing is Brown. Use Brown bearing inserts.


No. 1


No. 2


No. 3


No. 4


*No. 5


#For crankshaft main bearing only.

d.  When assembling, apply a liberal coat of motor oil to all bearing surfaces.


When applying final torque to the rod caps, observe the following procedures:

e.  Apply molybdenum disulfide grease to connecting rod bolt threads. Apply torque evenly to both ends of the cap. While tightening, if a torque of 2.0 m-kg (14.5 ft-lb) or more is reached, DO NOT STOP tightening until final torque is reached. If tightening is interrupted between 2.0 m-kg and 2.5 m-kg, loosen the nut to less than 2.0 m-kg and start again. Tighten to full torque specification without pausing.

Oil Pump and Clutch -- Inspection and Repair

J. Oil Pump

1. Check the clearance between housing and outer rotor.

Standard clearance:

0.09 ~ 0.15 mm

(0.0035 ~ 0.0059 in)

2. Check the clearance between outer rotor and inner rotor.

Standard clearance

0.12 mm (0.005 in) or less

3. Check the plunger for scratches and wear.

1. Relief valve plunger

K. Clutch

1. Clutch housing

a. Check the dogs on the clutch housing. Look for cracks and signs of galling on edges. If damage is moderate, deburr. If severe, replace the clutch housing.


Galling on the friction plate dogs of the clutch housing will cause erratic clutch operation.

b. Check the clutch housing bearing for damage. If damaged replace bearing.

2. Clutch boss

a.   The clutch boss contains a built-in damper beneath the first clutch plate (clutch plate 2). It is not normally necessary to remove the circlip and disassemble the built-in damper unless there is serious clutch chattering.

b.   Check splines on clutch boss for galling. If damage is slight to moderate, deburr; if it is severe, replace clutch boss.


Galling on clutch plate splines will cause erratic operation.

3. Friction and clutch plates

Check clutch steel plates and friction plates for heat damage. Measure friction plate thickness at 3 or 4 points. Measure

clutch plates for warpage with a dial gauge and stand. Replace clutch plate or friction plates as a set if any is faulty or beyond wear limits.



Wear limit

Friction plate thickness

3.0 mm (0.12 in)

2.8 mm (0.11 in)

Clutch plate warp limit

0.05 mm (0.0020 in)

1. Feeler gauge

4. Clutch actuating mechanism

1. Plate washer 2. Thrust bearing 3. Pull rod

a.   Check the pull rod rack gear teeth for wear and damage, replace if damaged.

b.  Check the pull rod thrust bearing for damage, replace if damaged.

c.   Check the clutch lever shaft pinion gear teeth for damage, replace if damaged.

5. Clutch springs

Measure the clutch spring free length. Replace the springs as a set if any is less than minimum free length.

Clutch spring minimum length: 39.1 mm (1.539 in)

Transmission -- Inspection and Repair

L. Transmission

1. Inspect each shift fork for signs of galling on gear contact surfaces. Check for bending. Make sure each fork slides freely on its guide bar.

2.    Roll the guide bar across a surface place. If the bar is bent, replace.

3.    Check the shift cam grooves for signs of wear or damage. If any profile has excessive wear and/or damage, replace cam.

4. Check the cam followers on each shift fork for wear. Check the ends that ride in the grooves in the shift cam. If they are worn or damaged, replace the shift forks.

5.    Check shift cam dowel pins and side plate for looseness, damage or wear. Replace as required.

6.    Check the shift cam stopper plate and circlip and stopper for wear. Replace as required.

7.   Check the transmission shafts using a centering device and dial gauge. If any shaft is bent beyond specified limit, replace shaft.

Maximum run-out: 0.08 mm (0.0031 in)

8.    Carefully inspect each gear. Look for signs of obvious heat damage (blue discoloration). Check the gear teeth for signs of pitting, galling or other extreme wear. Replace as required.

9.    Check to see that each gear moves freely on its shaft.

10.    Check to see that all washers and clips are properly installed and undamaged. Replace bent or loose clips and bent washers.

11.    Check to see that each gear properly engages its counterpart on the shaft. Check the mating dogs for rounded edges, cracks, or missing portions. Replace as required.

M. Starter Drivers

1. Electric starter clutch and gears

a.   Check the surface of the idle gear for pitting or other damage. If severe, replace the gear.

b.   Check the spring caps and the springs for deformation or damage. If severe, replace as necessary.

c.   Check the starter clutch bolts (alien screw) for looseness. If loose, remove the bolts and replace with new bolts. Apply a thread locking compound such as "LOCTITE" to threads and tighten to specified torque. Stake over the end of the bolts.

Starter clutch bolt torque: 3.0 m-kg (21.7 ft-lb)

d.  Check the "HY-VO" chain for damage and wear, replace if damaged.

e.   Check the "HY-VO" chain guide for damage, replace if damaged.

N. Crankcases and Strainer Cover

1. Check crankcase for cracks or other damage.

2.    Clean all oil passages and blow out with compressed air.

3.    Strainer cover: Apply a thread locking compound such as "LOCTITE" to strainer cover bolts during reassembly.

O. Bearing and Oil Seals

1. After cleaning and lubricating bearings, rotate inner race with a finger. If rough spots are felt, replace the bearing.


Bearings are most easily removed or installed if the housings are first heated to approximately 95°~12E?C (200°~250°F). Bring the case up to proper temperature slowly. Use an oven to avoid distortion.

2.    Check oil seal lips for damage and wear. Replace as required.

Middle Gear -- Inspection and Repair

P. Middle Gear

1. Damper disassembly


Disassembly of the middle gear damper requires the damper compressor (special tool) and a hydraulic press.

a. Place the middle drive shaft in a press with the damper compressor (special tool) in place as shown.

1. Damper compressor

b.   Press the damper spring and remove the spring retainers.

c.   Remove the spring seat, spring, and damper cams from the drive shaft.

2. Inspection

a. Inspect the damper cam surfaces. Check for smooth cam action and excessive wear on the cam surface. If cam surface is severely worn, replace damper assembly.

b.   Inspect the damper spring for fatigue, wear and damage. Replace as necessary.

c.   Check bearing movement for damage to balls, rouge spots, bearing looseness. Inspect gear teeth. If any gear tooth and/or bearing are damaged, the gear set and/or bearing must be replaced.

3. Middle drive/driven shaft bearing removal


The following procedures should be performed only if the bearing or gear is to be replaced.

a. Middle drive gear

1) Bend down the locking collar of the nut with a suitable center punch.

2) Support the middle drive shaft holder (special tool) in a vise securely and put

the drive pinion on it as shown. Remove the bearing holding nut with the 46 mm socket (special socket) and remove the bearing.

1. Middle drive shaft nut wrench (46 mm socket)

2. Middle drive shaft holder

b. Middle driven gear

1) Support the drive flange in a vise

securely. Remove the flange holding nut.


This holding nut has been locked with a thread locking compound, when reinstalling do not forget to apply a thread locking compound such as "LOCTITE" and punch.

2) Remove the drive flange from the driven shaft.


Driven gear shaft bearing should be replaced together with a bearing housing.

4. Middle gear reassembly

a. Middle drive gear bearing and damper

1) Install the bearing onto the drive pinion

and secure it with a new lock nut using

the middle drive shaft holder and special


Tightening torque:

11 m-kg (80 ft-lb)

2) Stake the locking collar of the nut to the slot on the drive pinion shaft.

3) Install the driven damper cam onto the drive pinion shaft with the cam lobes positioned 90° from the row of shaft oil holes. Positioning tolerance is ± 1 spline (1!?) from the90°position.

1. Oil hole

4) Install the drive damper cams, spring, spring seat, and retainers using a press and the damper compressor.

b. Middle driven gear

1) Install the new bearing housing assembly onto the driven pinion shaft.


Do not press the bearing outer race. Always press the inner race with care when installing.

2) Install the drive flange and new "O-ring" onto the driven gear shaft. Apply a thread locking compound such as "LOCTITE" to the shaft threads and tighten the nut to the specified torque.

Tightening torque:

12 m-kg (87 ft-lb)

3) Stake the nut with a center punch to lock as shown.

4) Install the new "O-ring" onto the bearing housing.

Upper Crankcase Reassembly


A. Important Information

1.    Gasket and seal

All gaskets and seals should be replaced when an engine is overhauled. All gasket surfaces and oil seal lips must be cleaned.

2.    Properly oil all mating engine and transmission parts and bearings during reassembly.

3.    Circlip

All circlips should be inspected carefully before reassembly. Always replace piston pin clips after one use. Replace distorted circlips.

When installing a circlip, make sure that the sharp edged corner is positioned opposit to the thrust it receives. See the sectional view below.

4. Lock washer/plate and cotter pin

All lock washers/plates and cotter pins must be replaced when they are removed. Lock washer/plate tab(s) should be bent over along the bolt or nut flat(s) after tightening the bolt or nut properly (see illustration).

Cotter pins should be replaced after one use.

B. Engine Assembly 1. Upper crankcase

a. Install the connecting rods onto the crankshaft with the proper connecting rod bearings and apply molybedenum disulfide grease to the bolt threads. Apply torque evenly to both ends of the cap.

I— CAUTION:--------------------------------------------1

While tightening, if a torque of 2.0 m-kg (14.5 ft-lb) or more is reached, DO NOT STOP tightening until final torque is reached.

If tightening is interrupted between 2.0 m-kg and 2.5 m-kg, loosen the nut to less than 2.0 m-kg and start again. Tighten to full torque specification without pausing.

Rod cap torque: 2.5 m-kg (18.1 ft-lb)

b- Install the proper cankshaft main bearings into the crankcase and place the crankshaft. Oil the bearings liberaly.


Do not forget to install the crankshaft oil seal (L.H.), blind plug (R.H.), "HY-VO" chain and cam chain on the crankshaft before installing. Also, install the chain guide into upper crankcase if removed.

c. Install the starter idle gear, shaft, stopper plate, and new lock plate. Tighten the bolt securely and bend the lock tabs along the bolt flats.

1. Lock washer

Tightening torque: 1.0 m-kg (7.2 ft-lb)

d.  Put the starter clutch and sprocket assembly in the "HY-VO" chain and lay it into the crankcase.

e.   Install the A.C.G. Generator shaft into the starter clutch assembly.

f. Install the "HY-VO" chain oil spray nozzle. The locating pin on the nozzle should be placed into the crankcase locating slot. Do not forget to install the new "O-ring" onto the nozzle.

1. O-ring

g. Install the new "O-ring" onto the bearing housing and install it with the panhead screw.

h. Install the transmission main axle assembly on the upper crankcase. Point the bearing locating pin toward the crankshaft and lav it on the case.

1. Bearing locating pin

i. Install the middle driven gear (without the middle drive pinion gear).

j. Install the middle driven gear shaft end bearing.

k. Install the dowel pin with "O-ring" into the crankcase.

Lower Crankcase Reassembly

2. Lower crankcase

a.   Install the shift cam and secure it with the guide pin. Install the stopper plate and bolt and tighten securely.

b.   Install the neutral switch.

c. Install the transmission drive axle assembly into the crankcase.

d. Install the 5th wheel gear and bearing onto the drive axle. Install the bearing cover. Be sure the "O-ring" is on the cover.

1. O-ring

e. Install the shift forks and guide bar. Each shift fork is identified by a number cast on its side. All the numbers should face the left side and numbered 1, 2, and 3 from left.

3. Crankcase assembly a. Apply Yamaha bond # 4 sealant or equivalent to the crankcase mating surface. Be very careful not to allow any sealant to come in contact with the oil gallery "O-ring" and crankshaft bearings. It is extremely important, however, that sealant be applied around the case stud holes. Apply sealant to within 2~3 mm (0.08 ~0.12 in) of the bearings.


Failure to apply sealant here will result in reduced oil pressure and possible crank seizure.

a. 2~3 mm (0.08~0.12 in) Do not apply sealant.

b. The crankcases are assembled by placing the upper case half on the bench and lowering the lower case onto it.


Be sure that shift fork No. 2 engages the groove in the 2nd pinion gear on the main axle.


Before installing and torquing the crankcase bolts, check to make sure the transmission is functioning properly by shifting it by hand with the shift cam.

c.   Start installation of the crankcase bolts with the center crankshaft area bolts. Place the two bolts without washers in the oil filter area.

d.  The crankcase bolts should be torqued in proper sequence. Refer to the tightening sequence in the illustration.





1. Engine ground wire 2. Battery ground wire

4. Oil pump and strainer cover

a.   Place the oil pump drive chain on the transmission main axle.

b.   Place the drive chain on the oil pump driven sprocket and install the pump on the crankcase. The "O-ring" should be installed properly.


c. Install the drive chain cover on the oil pump and secure with the 2 shouldered bolts and one normal 6 mm bolt.

Tightening torque: 1.0m-kg(7.2ft-lb)

d. Install the strainer cover and torque the bolts to the specification.

Tightening torque: 1.0m-kg(7.2ft-lb)

1. Wire clamps

Clutch and Shifter Reassembly

5. Clutch assembly

a. Install the thrust plate onto the transmission main axle.

1. Thrust plate

b. Install the oil pump drive sprocket onto the main axle without the spacer collar and place the oil pump drive chain on its sprocket.

1. Oil pump drive sprocket

c. Insert the spacer collar into the oil pump drive sprocket.

1. Spacer collar

d. Install the primary driven gear (clutch housing) without the bearing and inner spacer.


Be sure that the oil pump drive gear tabs engage the clutch housing grooves on it's back or the tabs will be damaged when tightening the clutch boss securing nut.

e. Installing the primary driven gear bearing and inner spacer into the clutch housing.

1. Driven gear bearing 2. Inner spacer

f. Install the large thrust plate and clutch boss onto the main axle.

g. Install a new lock washer and nut and tighten the nut to the specified torque. Use the clutch boss holder (special tool).

1. Clutch boss holder

Tightening torque: 7.2 m-kg (52 ft-lb)

h. Bend the lock washer tabs along the nut flats.

1. Lock tab

i. Install the clutch plates and friction plates alternately on the clutch boss, starting with a friction plate and ending with a friction plate.

j. Install the plate washer, thrust bearing, and clutch pull rod into the clutch pressure plate from inside.

1. Pull rod 2. Thrust bearing 3. Plate washer

k. Install the pressure plate assembly onto the clutch boss.


Pressure plate has a dot on it which must line up with the dot on clutch boss.

I. Install the clutch springs and screws. Tighten the screws.

Clutch screw torque: 1.0 m-kg (7.2 ft-lb)

m. Set the gear of the clutch pull rod on the pressure plate facing approximately 45° from horizontal toward the rear; set the clutch lever (if installed) on the right crankcase cover parallel to the gasket surface and install the cover to the crankcase. Do not forget to install two dowel pins.

n. If the clutch lever has been removed, install the lever return spring and lever on the shaft after installing the right crankcase cover. In this case make sure that the punch mark on the lever should align with the mark on the crankcase cover when pushing the lever towards the front by hand and then install the circlip.

Middle Gear Reassembly

6. Middle gear (installation only, refer to page 67 for the middle gear adjustment)

a. Install the middle drive gear assembly with the proper size of shim(s) and secure it with the bearing retainers and new "TORX" screws.

Tightening torque: 2.5 m-kg (18 ft-lb)

1. Shims

b. Stake the screw heads to the dents on the bearing retainers with a center punch.

c. Install the driven gear assembly with the proper size of shims and secure it with the bolts. Apply a thread locking compound such as "LOCTITE" to the bolt threads,

Tightening torque:

2.5 m-kg (18.1 ft-lb)

1. Shims

d. Install the middle gear case half moon seal onto the crankcase.

1. Seal

7. Shifter assembly

a. Install the shift shaft assembly with the stopper lever.

b. Install the shift lever assembly with the positioning spring is properly located on the stopper pin and the teeth should be set properly as shown.


c. Install the left crankcase cover (shifter cover) using a new gasket. Make sure the wire harness clips are properly positioned.

Tightening torque: 1.0m-kg(7.2ft-lb)

Generator, Starter and Pick-up Coil Reassembly

8. A.C. Generator

a. Install the rotor onto the shaft and

tighten the bolt using the rotor holding

tool (special tool) as shown.

1. Rotor holding tool

Tightening torque: 5.5 m-kg (39.8 ft-lb)

b. Install the stator coil assembly onto the crankcase and align the grooves on the stator core with the bolt holes on the crankcase.

c. Install the A.C.G. cover assembly and tighten the bolts to the specification. Do not forget to install the new gasket.

Tightening torque: 1.0 m-kg (7.2 ft-lb)

9. Starter motor

a.   Route the A.C.G. lead wires as shown.

b.   Install the starter motor and tighten the bolts to the specification.

Tightening torque: 1.2 m-kg (8.7 ft-lb)


Be careful the "O-ring" is not damaged when installing the starter motor.

1. O-ring 2. A.C.G. lead wires

10. Pick-up coil assembly

a.   Install the pick-up coil assembly onto the crankcase.

b.   Install the timing plate on the crankshaft and tighten the bolt to the specification.


Note that there is the locating pin on the crankshaft and the corresponding slot in the timing plate which must be aligned to install the timing plate.

Pistons and Cylinder Reassembly

11. Pistons and Cylinder a. Install the pistons on the rods. The arrow on the piston must point to the front of the engine.


Before installing the piston pin clips, cover

the crankcase with a clean rag so you will

not accidentally drop the circlip into the


Always install new piston pin circlips.

b. Install the rear chain guide on its pivot. Tighten the holding bolt until it stops and then loosen 1/4 turn and then tighten the lock nut.

1. Holding bolt 2. Rear chain guide

c. Install the new cylinder base gasket and dowel pins. Install the new "O-rings" to the right side dowei pins.

d. Set the crankshaft so that the all pistons are equal height and align the piston rings as shown.


Make sure the ends of the oil ring expanders are not overlapped.


Manufacturer's marks or numbers stamped on the rings are on the top side of the rings. Coat the pistons and rings well with oil.

e. Install the piston ring compressors (special tool) and piston bases (special tool). Four piston bases are required.

1. Piston bases 2. Piston ring compressors

f. Tie the cam chain with a piece of mechanic's wire and feed it through the chain opening. Carefully lower the cylinder onto the pistons. Remove the ring compressors and piston bases and repeat this procedure for pistons 1 and 4.

g. Install the cylinder securing nut (front side) and tighten it to the specification.

Tightening torque:

2.0 m-kg (14.5 ft-lb)

h. Set the dial gauge on the No. 1 piston head center as shown to find the No. 1 piston top dead center and check whether the "1" mark on the timing plate and stationary pointer are aligned or not. If not, loosen the pointer securing screw and adjust.

Cylinder Head and Camshaft Reassembly

12. Cylinder head and Cam shafts 

a. Install the new cylinder head gasket. Install the dowel pins and "O-rings". Locate the cam chain cavity cylinder seal with the tabs down.

b.   Install the cylinder head onto the cylinder. Pull the cam chain through the cylinder head as it is installed. Tie the cam chain so that it does not fall into the crankcase.

c.   Place the upper cylinder head nuts and washers in place. Follow the illustration for the proper tightening sequence. Torque all nuts in two stages and final torque the upper nuts to the specification.

Tightening torque: 3.2 m-kg (23.1 ft-lb)

Don't forget the lower nuts on the front and rear of the cylinder head. Torque to the specification.

Tightening torque: 2.0 m-kg (14.5 ft-lb)

a. Copper washers


Tighten the nuts in two stages, 1/2 torque value and then full torque value. Also lubricate the bolt threads with the engine oil to achieve proper torque values.

d. Install the front cam chain guide being certain that it is in its holder down below.

e. Rotate the engine in a counterclockwise direction until the crankcase pointer and "T" mark on the timing plate are aligned.

f.   With the cylinders No. 1 and 4 at the top dead center, slip the cam chain over the sprocket,

g.   Lubricate all cam caps and cam bearings surfaces liberally with oil.

h. Place the cam caps in their proper positions. The caps are identified "1-1" through "I-3" for intake and "E-1" through "E-3" for exhaust. Install the bolts only finger tight.

r— CAUTION:---------------------------------------

The cam caps must be tightened evenly or damage to the cylinder head, cam caps and cam will result. The spaces between the

caps and cylinder head should be equal.

I. Torque the cam cap bolts in two stages and final torque to the specification.

Tightening torque: 1.0 m-kg (7.2 ft-lb)

13. Cam chain, cam sprockets and chain tensioner a. Rotate each cam shaft until the dot on the cam is aligned with the arrow on the center cam cap.

|— CAUTION:-------------------------------------------.

Use extreme caution when rotating the cams. Two possible dangers exist. First, the wrench may contact the head and fracture it. Or second, a valve may become bent if the cam is turned the wrong way.

). Carefully lift the cam chain from the exhaust cam sprocket and pull upward to remove any slack in the chain between the crankshaft and the exhaust cam sprocket. With all slack removed, place the chain back on the cam sprocket.

;. Grip each sprocket simultaneously and place them on the camshaft shoulders while continuing to keep tension on the chain from the crankshaft to the exhaust sprocket.


Use only the special hardened shouldered bolts to install the cam chain sprockets to the cams.

Make sure the rollers of the cam chain are centered on both chain guides.

d.   Rotate the sprockets slightly to align the bolt holes and insert one special bolt in each sprocket.

NOTE: ------------------------------------------------------

Tighten only finger tight at this time.

e.   Install the center chain guide.

f. Rotate the crankshaft counterclockwise and align the "C" mark on the timing plate with the timing pointer.

g. Compress the cam chain tensioner and lock in the retracted position. 

h. Install the chain tensioner to the engine and torque the bolts to the specification.

Tightening torque: 1.0 m-kg (7.2 ft-lb)

i. Release the tensioner holding bolt, an audible click will be heard when the tensioner is released.

j. Torque the holding bolt and the lock nut to the specifications.

Holding bolt torque:

0.6 m-kg (4.3 ft-lb) Lock nut torque:

0.9 m-kg (6.5 ft-lb)

k. Rotate the crankshaft more than one full revolution and align the "T" mark on the timing plate with the timing pointer. With the crankshaft at the "T" mark, the dots on the cams should be aligned with the raised arrows on the center cam caps. If they are not aligned, disassemble the sprockets and chain tensioner and repeat above procedures. 

I. Rotate the crankshaft and install the two remaining shoulder bolts into the cam sprockets. Torque all four sprocket holding bolts to the specification.

|— CAUTION:-----------------------------------------.

Be sure to attain the specified torque value to avoid the possibility of these bolts coming loose and causing serious damage to the engine.

Tightening torque: 2.0 m-kg (14.5 ft-lb)

m. Adjust all valves as described in the "PERIODIC INSPECTIONS AND ADJUSTMENTS".

n. Install the cylinder head cover with a new gasket.

o. Install the left and right crankcase covers. The left crankcase cover (pickup coil cover) is required a gasket.

Middle Gear Adjustment

C. Middle Gear Servicing

1.    Disassembly

Refer to page 39 for disassembly.

2.    Inspection

Refer to page 52 for inspection.

3.    Gear lash check


The middle gear lash can be checked only when the gears are installed in the crankcase.

a. Install the middle drive pinion holder (special tool) on the crankcase to hold the drive gear stationary during the lash measurement.


Before installing the tool, loosen the holder bolt all the way out and after installation tighten this bolt as tight as necessary (finder tight is generally sufficient).

1. Middle drive pinion holder

b. Set the dial gauge to the middle drive flange as shown and gently rotate the drive flange back and forth. Note the lash measurement on the dial gauge.

Middle gear lash: 0.1 ~ 0.2mm(0.004~ 0.008 in)

c. Check this engagement at 4 positions. Rotate the drive flange 90° each time and repeat the gear lash check.


If the gear lash exceeds the specified limit and adjustment is necessary, the engine or swing arm should be removed from the motorcycle.

4. Gear lash adjustment

a. Install the driven gear housing assembly into the crankcase leaving about a 2 mm (0.080 in) gap between the housing and crankcase and install the two bolts to the bearing housing 180° opposite to each other.

a. 2 mm (0.080 in)

b. Install the middle drive shaft holder and dial gauge (refer to "Middle gear lash check").

c. Slowly tighten the bolts alternately until the dial gauge lash measurement reaches 0.2 mm (0.008 in).

d. Measure the gap between the driven gear bearing housing flange and the crankcase with a feeler gauge. This is the shim size required.

1. Feeler gauge

e. Install the proper sized shims as shown and tighten the driven gear housing to the specified torque.

Recheck the gear lash, it should be within the specification, if not readjust the shims.

Gear lash: 0.1 - 0.2 mm (0.004-0.008 in

5. Drive gear positioning


When the following part(s) is replaced with new one(s), drive gear positioning is necessary

a.   Crankcase

b.   Middle gears

c.   Middle gear bearing housing

a. The shim thickness necessary for the drive gear positioning can be calculated from the information found on the upper crankcase and on the drive gear shaft.

b. To find shim thickness "A" use the


A = c —a — b


a= a numeral (usually a decimal number) printed on the shaft end as shown above and either added to or subtracted from the nominal size "43".

b = a bearing thickness (considered constant)

c = a numeral (usually a decimal number) found on the upper crankcase half near the main bearing selection numbers and added to the nominal size "60".

Distance "b"^ 16.94 mm


1)lf the shaft is marked +03 ...... "a" is

43.03 mm.

2)   "b" is 16.94 mm.

3) If the crankcase is stamped "45" ..... "c"

is 60.45 mm.

A = c — a —b

A = 60.45 ^16.94-43.03

A = 0.48

Then the necessary shim thickness is

0.48 mm.

c. Shim size are supplied in the following thicknesses:

0.15 mm, 0.20 mm, 0.30 mm, 0.40 mm, and 0.50 mm.

Because the shims can only be selected in 0.05 mm increments the following chart should be used when encountering last digits that are not 5 or zero (0):

Last digits








Remounting the Engine


1. Reverse the applicable removal steps to reinstall.

CAUTION: Always use new bolts in the drive shaft coupling.

2. Install and tighten the engine mounting bolts.

Engine mounting bolt torque:

8 mm bolt: 2.0 m-kg (14.5 ft-lb) 
10 mm bolt: 4.2 m-kg (30.4 ft-lb) 
12 mm bolt: 7.0 m-kg (50.6 ft-lb)

3. Install the oil filter element into the filter cover and install a new "O-ring". Make sure the "O-ring" is positioned properly.

1. O-ring

Oil filter mounting bolt torque: 1.5 m-kg (11.0 ft-lb)

4. Install and tighten the engine oil drain plug and middle gear drain plug.

Engine oil drain plug torque: 4.3 m-kg (31.0 ft-lb)

Middle gear drain plug torque: 2.4 m-kg (17.5 ft-lb)

5. Add oil to the engine and middle gear case.

Oil quantities: 3.6L (3.8 US. qt.)

NOTE: The oil quantities are for an overhauled engine.


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A. Section View

B. Specifications

Main jet


Jet needle


Needle jet


Starter jet


Fuel level


Pilot screw


Float valve seat


Engine idle speed

1,050 r/m in


The pilot screw settings are adjusted for maximum performance at the factory with the use of specialized equipment. Do not attempt to change these settings. If all other engine systems are functioning correctly, any changes will decrease performance and cause increased exhaust emissions.

C. Disassembly


Separation of the carburetor is not recommended. Usual disassembly for cleaning and inspection is not necessary to separate the carburetors. The carburetor body support screws are locked with a locking compound such "LOCTITE". If the carburetors are separated, misalignment will result.

1. Loosen the starter lever securing screws and remove the starter lever shaft, bushes, and levers. Note the positions of the bushes.

2. Remove the vacuum chamber cover and remove the spring and diaphragm (vacuum piston).


Note that there is the tab on the rubber diaphragm. There is the matching recess in the carburetor body for the diaphragm tab.

3. Remove the jet cover securing screw and remove the cover.

1. Jet cover

4. Remove the screws holding the float chamber cover and remove the cover. The main and pilot jets are located in

the float bowl. Remove the jets if necessary.

1. Pilot jet 2. Main jet

5. Pull out the float pivot pin. Remove the float assembly. Be careful to not lose the float valve under the float arm. Remove the float valve seat.

1. Float valve seat

6.    Reassemble in reverse order. Pay close attention to the installation of the vacuum piston diaphragm and the location of each jet.

7.    If the carburetors should be separated, care must be taken so that they are put together in place according to the following procedures:

a. Place the carburetors on a surface plate and install the lower support plate. Apply a thread locking compound such as "LOCTITE" and tighten the screws securely while holding the carburetor body.

1. Lower support plate 2. Surface plate


When reassembling, the surface plate should be used for the proper carburetor alignment.

b. Install the upper support plate. Apply a thread locking compound such as "LOCTITE" to the support screw threads and tighten the screws securely.

D. Inspection

1.   Examine the carburetor body and fuel passages. If contaminated, wash the carburetor in a petroleum-based solvent. Do not use caustic carburetor cleaning solutions. Blow out all passages and jets with compressed air.

2.   Examine the condition of the floats. If the floats are damaged, they should be replaced.

3.   Inspect the float needle valve and seat for wear or contamination. Replace these components as a set.

4. Inspect the vacuum piston and rubber diaphragm. If the piston is scratched or the diaphragm is torn, the assembly must be replaced.

1. Vacuum piston 3. Set spring

2. Needle jet                4. Needle jet cover

5. Inspect the starter plunger for damage, If damaged, replace.

E. Adjustment

Fuel level 


Before checking the fuel level, note the following:

1.    Place the motorcycle on a level surface.

2.   Adjust the motorcycle position by placing a suitable stand or a garage jack under the engine so that the carburetor is positioned vertically.

1.    Connect the level gauge (special tool) or a vinyl pipe of 6 mm (0.24 in) in inside dia. to the float bowl nozzle left or right side carburetor.

2.   Set the gauge as shown and loosen the drain screw.

1. Level gauge 2. Drain screw

3.    Start the engine and stop it after a few minutes of run. This procedure is necessary to obtain the correct fuel level. Make sure the fuel petcock is "ON" or "RES" position.

4,    Note the fuel level and bring the gauge to the other end of the carburetor line and repeat step 3 above. Note the fuel level again and compare it with the previous gauge reading. They should be equal. If not, place a suitable size of wooden piece or the like under the center stand and adjust.

5. Check the fuel level one by one. The level should be in the specified range.

Fuel level: 3± 1 mm (0.118 ± 0.039 in) below from the carburetor mixing chamber body edge.

6. If the fuel level is incorrect, remove the carburetor assembly from the motorcycle and check the fuel valve(s) and float assembly(s) for damage.

7. If no damage is found, correct the fuel level by slightly bending the float arm tang. Recheck the fuel level.

1. Float arm tang


Refer to "CHAPTER 2" for the air cleaner maintenance.

Chapter 5, CHASSIS

Wheels and Brakes




A. Removal

1.    Place the motorcycle on the center stand.

2.    Remove the cotter pin and wheel axle

3. Remove the speedometer cable holder securing bolt.

4. Loosen the pinch bolt securing the axle.

1. Pinch bolt

5. Remove the axle shaft and the front wheel. In this case, make sure the motorcycle is properly supported.


Do not depress the brake lever when the wheel is off the motorcycle as the brake pads will be forced to shut.

B.   Front Axle Inspection

Remove any corrosion from the axle with fine emery cloth. Place the axle on a surface plate and check for bends. If bent, replace axle. Do not attempt to straighten a bent axle.

C.   Front Wheel Inspection

This motorcycle is equipped with aluminum wheels designed to be compatible with either tube or tubeless tires.

Tubeless tires are installed as standard equipment.


Do not attempt to use tubeless tires on a wheel designed for use only with tube-type tires. Tire failure and personal injury may results from sudden deflation.


Tube-type Wheel >

Tube-type Tires Only


Tubeless-type Wheel >

Tube-type or 
Tubeless tires




When using tube-type tires, be sure to install the proper tube also.

Refer to 'Tubeless Tire and Aluminum Wheel Manual" for the proper tubeless and aluminum wheel servicing.

1.    Check for cracks, bends or warpage of wheels. If a wheel is deformed or cracked, it must be replaced.

2.    Check wheel run-out. If the deflection exceeds the tolerance below, check the wheel bearings or replace the wheel as required.

Rim-run-out limits:


- 2 mm (0.079 in)


- 2 mm (0.079 in)

3.    Check wheel balance. Rotate the wheel lightly several times and observe resting position. If the wheel is not statically balanced, it will come to reset at the same position each time. Install an appropriate balance weight at lightest position (at top).


The wheel should be balanced with the brake disc installed.

4.    After installing a tire, ride conservatively to allow the tire to seat itself on the rim properly. Failure to allow proper seating may cause tire failure resulting in damage to the motorcycle and injury to the rider.

5.    After repairing or replacing a tire, check to be sure the valve stem lock nut is securely fastened. If not, torque it as specified.

Tightening torque: 0.15 m-kg (1.1 ft-lb) !

D. Replacing Wheel Bearings

If the bearings allow play in the wheel hub or if wheel does not turn smoothly, replace the bearings as follows:

1.    Clean the outside of the wheel hub.

2.    Drive the bearing out by pushing the spacer aside and tapping around the perimeter of the bearing inner race with a soft metal drift pin and hammer. The spacer "floats" between the bearings. Both bearings can be removed in this manner.


Eye protection is recommended when using striking tools.

3.    To install the wheel bearing, reverse the above sequence. Use a socket that matches the outside race of the bearing as a tool to drive in the bearing.


Do not strike the center race or balls of the bearing. Contact should be made only with the outer race.

E.Installing Front Wheel

When installing the front wheel, reverse the removal procedure. Note the following points:

1.    Lightly grease the lips of the front wheel oil seals and the gear teeth of speedometer drive and driven gears. Use lightweight lithium soap base grease.

2.    Make sure there is enough gap between the disc pads to slide the disc into place.

3.    Make sure the projecting portion (torque stopper) of the speedometer housing is positioned correctly.

1. Torque stopper

4. Tighten the axle nut and install a new cotter pin.

Axle nut torque: 10.7 m-kg (77.4 ft-lb)

NOTE: Tighten the pinch bolts temporarily before tightening the axle nut.

5.    Install the front fender.

6.    Before tightening the pinch bolts, stroke the front forks several times to make sure of proper fork operation. With the pinch bolts loose, work the left fork leg back and forth until the proper clearance between the disc and caliper bracket are obtained.

7.    Tighten the left and right pinch bolts.

Axle pinch bolt torque: 2.0 m-kg (14.5 ft-lb)




A. Removal

1.    Place the motorcycle on the center stand.

2.    Remove the tension bar and the brake rod from the brake shoe plate. The tension bar can be removed by removing the cotter pin and nut from the tension bar bolt. The brake rod can be removed by removing the adjuster.

1. Adjuster     2. Tension bar     3. Brake rod

3. Remove the axle nut cotter pin and axle nut.

4. Loosen the rear axle pinch bolt and pull out the rear axle.

1. Pinch bolt

5. Move the wheel to the right side to separate it from the final gear cases and remove the rear wheel.

B. Checking Brake Shoe Wear

1. Measure the outside diameter at the brake shoes with slide calipers.

Front brake shoe diameter:

180 mm (7.09 in) Replacement limit:

176 mm min. (6.93 in)

a. Measuring points

2. Remove any glazed areas from the brake shoes using coarse sand paper.

C.   Brake Drum

Oil or scratches on the inner surface or the brake drum will impair braking performance or result in abnormal noises.

Remove oil by wiping with a rag soaked in lacquer thinner or solvent.

Remove scratches by lightly and evenly polishing with emery cloth.

D.  Brake Shoe Plate

Remove the camshaft and grease. If the cam face is worn, replace.


Before removing the cam lever, put a match mark on the cam lever and camshaft to indicate their positions for easy assembly.

E.    Rear Axle Inspection

(See Front Wheel, Axle Inspection Procedure.)

F.    Replacing Wheel Bearings

Rear wheel bearing replacement is similar to the procedure for the front wheel.

G.   Rear Wheel Inspection

(See Front Wheel, Inspection Procedures)

H. Installing Rear Wheel

1.    Lightly grease lips of rear wheel oil seals.

2.    Install the wheel assembly and axle.


When installing the rear wheel, be sure the splines on the wheel hub fit into the final gear case. Lightly apply grease to the gear teeth.

Always use a new cotter pin on the axle nut.

Tightening torque:

Axle nut: 10.7 m-kg (77.4 ft-lb) Axle pinch bolt: 0.6 m-kg (4.5 ft-lb)



Disc brake components rarely require disassembly. Do not disassemble components unless absolutely necessary. If any hydraulic connection in the system is opened, the entire system should be disassembled, drained, cleaned and then properly filled and bled upon reassembly. Do not use solvents on brake internal components. Solvents will cause seals to swell and distort. Use only clean brake fluid for cleaning. Use care with brake fluid. Brake fluid is injurious to eyes and will damage painted surfaces and plastic parts.

A. Caliper Pad Replacement


Disc brake components rarely require disassembly. Do not disassemble components unless absolutely necessary. If any hydraulic connection in the system is opened, the entire system should be disassembled, drained, cleaned and then properly filled and bled upon reassembly. Do not use solvents on brake internal components. Solvents will cause seals to swell and distort. Use only clean brake fluid for cleaning. Use care with brake fluid. Brake fluid is injurious to eyes and will damage painted surfaces and plastic parts.

It is not necessary to disassemble the brake caliper and brake hose to replace the brake pads.

1.    Remove the front fender and front wheel.

2.    Remove the Phillips screw that holds the brake pads.

3.    Pull the caliper cylinder out of the caliper frame.

4.    Install new brake pads. Always replace pad as a set. Replace the following when pads are replaced.

a.   Pad screw

b.  Shims

c.   Pad spring

d.   Pads

1.  Pad screw
2. Shim
3. Pad spring
4. Pad

5. Lightly grease the surfaces of the shim and of the pad spring where they contact the pad.



B. Caliper Disassembly

1.    Sleeve
2.    Bushing boot   
3.    Bleed screw  
4.    Indicator cap  
5.    Pad screw
6.    Piston
7.    Piston seal
8.    Dust cover
9.    Circlip
10.    Pad spring
11.    Pad
12.    Shim


1. Remove the caliper brake hose. Allow fluid in the caliper assembly to drain into a container.

2.    Place the open hose end into the container and pump the old fluid out carefully.

3.    Remove the caliper support bolt and the pad securing screw as described in the Caliper Pad Replacement procedure (Page 9).

4.    Remove the caliper assembly from the caliper frame.

5.    Remove the retaining ring and the dust seal.

6.    Remove the piston.


Cover the piston with a rag. Use care so that the piston does not cause injury as it is expelled from the cylinder.

G. Brake Inspection and Repair

7. Remove the piston seal.

Recommended Brake Component

Replacement Schedule: Brake pads; As required Piston seal, dust seal; Every two years Brake hoses; Every four years Brake fluid; Replace only when brakes are disassembled

1.    Replace the caliper piston if it is scratched.

2.    Replace any brake pad worn beyond limits. Always replace the brake pads as a set.

Wear limit: 1.5 mm (0.06 in)

See Caliper Pad Replacement procedure for a listing of the parts to be replaced when pads are replaced.

1. Wear limit

3.    Replace piston and dust seals if damaged. Replace seals every two years.

4.    Inspect master cylinder body. Replace if scratched. Clean all passages with new brake fluid.

5.    Inspect the brake hoses. Replace every four years or immediately if cracked, frayed, or damaged.

6.    Check for wear and deflection of disc.

Maximum deflection: 0.15 mm (0.006 in)

Minimum disc thickness: 44.5 mm (0.18 in)

1. Dial gauge 2. Disc

If disc is worn beyond minimum thickness or deflection exceeds specified amount, replace disc.

H. Brake Reassembly

1.    All internal parts should be cleaned in new brake fluid only. Internal parts should be lubricated with brake fluid when installed.

2.    Caliper Reassembly

Replace the following parts whenever a caliper is disassembled: bleed screw and cap, boot bushing, piston seal, dust seal, and retaining ring. a. Install the piston seal and piston. Place the caliper cylinder into the caliper frame.

b.   Install the pad spring, shims and pads.

c.   Apply a thread locking compound such as "LOCTITE" to the support bolt.

d.   Install the caliper assembly on the front fork.

Support bolt (caliper cylinder) torque: 1.8 m-kg (13.0 ft lb)

Support bolt (caliper bracket) torque: 2.6 m-kg (18.8 ft-lb)

3. Attach the brake hoses.

Brake hose torque: 2.6 m-kg (18.8 ft-lb)

4. Master-cylinder reassembly

Reassemble master cylinder as shown in illustration.

Brake hose torque: (all brake union bolts) 2.6 m-kg (18.8 ft-lb)


1.  Copper washer
2. Union bolt
3. Joint
4. Cylinder kit

5. Brake disc assembly

If the brake disc has been removed from the hub or is loose, tighten the bolts. Use new locking washers and bend over the locking tabs after the bolts are tightened.

Disc bolt torque: 20m-kg(14.5ft-lb)

b. Connect the clear plastic tube of 4.5 mm (3/16 in) inside diameter tightly to the caliper bleed screw. Put the other end of the tube into a container.

c.   Slowly apply the brake lever several times. Pull in the lever. Hold the lever in "on" position. Loosen the bleed screw. Allow the lever to travel slowly toward its limit. When the limit is reached, tighten bleed screw. Then release the lever.

d.   Repeat step "c" procedure until all air bubbles are removed from system.

NOTE: If bleeding is difficult, it may be necessary to let the brake fluid system stabilize for a few hours. Repeat the bleeding procedure when the tiny bubbles in the system settle out.

J. Air Bleeding

WARNING: If the brake system is disassembled or if any brake hose has been loosened or removed, the brake system must be bled to remove air from the brake fluid. If the brake fluid level is very low or brake operation is incorrect, bleed the brake system.

Failure to bleed the brake system properly can result in a dangerous loss of braking performance.

a. Add proper brake fluid to the reservoir. Install the diaphragm, being careful not to spill or overflow the reservoir.



Front Forks and Steering Head



A. Removal and Disassembly 


Securely support the motorcycle so there is no danger of it falling over.

1.    Disconnect the speedometer cable. Disconnect the brake caliper and remove the front wheel. Place a wooden wedge or other object into the caliper assembly to keep the brake pads from falling out. Remove the front fender.

2.    Remove the rubber cap from the top of each fork.

3.    The spring seat and fork spring are retained by a stopper ring (spring wire circlip). It is necessary to depress the spring seat and fork spring to remove the stopper ring. Remove the stopper ring by carefully prying out one end with a small screwdriver.

4.    Place an open container under each drain hole. Remove the drain screw from each outer tube.


Do not allow oil to contact the disc brake components. If any oil should contact the brake components it must be removed before the motorcycle is operated. Oil will cause diminished braking capacity and will damage the rubber components of the brake assembly.

5.    Loosen the pinch bolt on the steering stem and the two pinch bolts crown and remove fork.

6.    Remove the Allen bolt from the bottom of the fork assembly while holding the inner tube with the front fork cylinder comp. holder (special tool). Pull the inner tube out of the outer tube.

To remove the fork seal. Pry out the dust seal and remove the spring clip over the oil seal. Pry out the oil seal, being very careful to not damage the fork tube surfaces.

1. Dust seal

B. Inspection

1. Examine fork inner tube for scratches and straightness. If the tube is scratched severely or bent, it should be replaced.


Do not attempt to straighten a fork tube, since this may weaken the part dangerously.

2.    Check the seal outer seat. If leakage is from this area, replace the seal. If this does not cure the leakage, replace the outer tube.

3.    Check the outer tube for dents. If any dent causes the inner tube to "hang up" during operation, the outer tube should be replaced.

4.    Check the free length of the springs.

Fork spring free length: 606 mm (23.86 in;

5. Check the "O-ring" on the spring seat. If damaged, replace the "O-ring".

C. Assembly

1.    Make sure all components are clean be-fore assembly. Always install a new fork seal. Do not re-use a seal.

2.    Apply oil to the fork seal and install the seal by pressing in with a large socket. Install the retaining clip and dust seal.

3.    Install the inner tube into the outer tube. Install and tighten alien bolt and washer.

The assembly procedure is the reverse of

the disassembly procedure.


When installing the fork springs, the greater pitch should be at the bottom. The main fork spring has a small coil diameter at the bottom.

1.Top    2. Smaller pinch

4. Reinstall the spring seat. 


Always use a new stopper ring (spring wire circlip).


A. Adjustment

Refer to "D. Reassembly" for steering head adjustment procedure.

B. Removal

1.    Remove the front wheel, front forks and handlebars.

2.    Remove the front brake pipe junction.

3. Loosen the steering stem (upper bracket) pinch bolt.

4. Remove the stem bolt and steering crown.

5. Remove the top fitting nut (ring nut).

6.   Support the steering stem (under bracket) and remove the bottom fitting nut (ring nut).

7.    Remove the top bearing race and all of the bearing balls from the upper bearing

Ball quantity (upper and lower): 38 pieces.

C. Inspection

1.   Wash the bearings in solvent.

2.    Inspect the bearings for pitting or other damage. Replace the bearings if pitted or damaged. Replace the races when bearing balls are replaced.

3.    Clean and inspect the bearing races. Spin the bearings by hand. If the bearings are not smooth in their operation in the races, replace bearing balls and races.

1. Bearing race

D. Reassembly

1. Grease the bearings and races with wheel bearing race.

2.    Install the steering stem (under bracket), bearing balls, and races.

3.    Install the bottom fitting nut. Tighten it to approximately 2.5 m-kg (18 ft-lb) and loosen it approximately 1/4 turn.

4.    While holding the bottom fitting nut with the ring nut wrench, tighten the top fitting nut securely.

5.    Continue reassembly in the reverse of disassembly order.

6.   When assembly is complete, check the steering stem by turning it from lock to lock. If there is any binding or looseness, readjust the steering stem tightness.

Pinch bolt torque: 2.0 m-kg (14.5 ft-lb)

Steering stem bolt torque 5.4 m-kg (39.1 ft-lb)


Swing Arm, Rear Shocks, Cables and Fittings


A. Inspection

1. Free play inspection

Remove the rear wheel and both shock absorbers. Grasp the swing arm and try to move it from side to side as shown. There should be no noticeable side play.

2. The swing arm is mounted on tapered bearings. Move the swing arm up and down as shown. The swing arm should move smoothly, without tightness, binding or rough spots that could indicate damaged bearings.

B. Adjustment

1.    Remove the pivot shaft cap from the right side of the swing arm.

2.    Loosen the right pivot shaft lock nut and tighten the pivot shaft (clockwise) to 0.5-0.6m-kg(43~52in-lb).

3. Tighten the pivot shaft lock nut.


Do not allow the pivot shaft to turn while tightening the lock nut.

Pivot shaft lock nut torque: 10m-kg (72.3ft-lb)

C. Removal

1.    Remove the middle gear flange holding bolts.

2.    Remove the rear wheel and shock absorbers.

3.    Remove the final gear assembly.

4.    Install the drive shaft puller attachment (special tool) on the side hammer bolt (special tool). Insert the 2 arms of the puller into the mouth of drive shaft housing. Tighten the 2 arms around the toothed flange of the drive shaft out of the universal joint. Pull out the drive shaft from the housing.

1.  Drive shaft     2.  Drive shaft puller      3. Slide hammer

5. Remove the swing arm pivot caps, the pivot shafts and the swing arm.

D. Inspection and Lubrication

1. Remove the oil seals and the bearings. Inspect the bearings for pitting or other damage. Make sure that the bearings roll freely. If a bearing is damaged, both bearings and both sets of inner and outer bearing races should be replaced.


Do not use compressed air to spin the bearings dry. This causes damage to the bearing surfaces.


When installing new bearings, grease liberally with lithium base, waterproof wheel bearing grease.

2.    Always replace the grease seals when bearings are removed.

3.    Examine the rubber boot for damage. Replace if damaged.

E. Installation

Installation of the swing arm can be accomplished by reversing the removal procedure. Observe adjustment procedures for obtaining equal frame/swing arm spacing.

Tightening torque: Left side pivot shaft: 10 m-kg (72.3 ft-lb) Right side pivot lock nut:

10 m-kg (72.3 ft-lb)


A lock washer for left side pivot bolt must be replaced with a new one and the tab should be bent over along the bolt flat after tightening.

1. Lock washer 


A.   Removal

1. Remove one (1) rear shock absorber at a time, inspect and reinstall before removing the other.

B.   Inspection

1.    Check the rod. If it is bent or damaged, replace the shock absorber.

2.    Check for oil leakage. If oil leakage is evident, replace the shock absorber.

3.    Operate shock absorber rod to check damping. There should be no noticeable damping as the shock extends.

4.    Install the shock absorber on the motorcycle.

Tightening torque:

3.0 m-kg (21.7 ft-lb)

CABLE AND FITTINGS A. Cable Maintenance


See Maintenance and Lubrication intervals charts. Cable maintenance is primarily concerned with preventing deterioration through rust and weathering and providing proper lubrication to allow the cable to move freely

within its housing. Cable removal is straight forward and uncomplicated. Removal will not be discussed within this section.


Cable routing is very important. For details of cable routing, see the cable routing diagrams at the end of this manual. Improperly routed or adjusted cables may make the motorcycle unsafe for operation.

1.    Remove the cable.

2.    Check for free movement of cable within its housing. If movement is obstruced, check for fraying or kinking of the cable strands. If damage is evident, replace the cable assembly.

3.    To lubricate the cable, hold it in a vertical position. Apply lubricant to the uppermost end of cable. Leave it in the vertical position until lubricant appears at the bottom. Allow any excess to drain and reinstall the cable.


Choice of lubricant depends upon conditions and preferences. However, a semi-drying chain and cable lubricant will perform adequately under most conditions.

B. Throttle Maintenance

1.    Remove the Phillips head screws from throttle housing assembly and separate the two halves of housing.

2.    Disconnect the cable end from the throttle grip assembly and remove the grip assembly.

3.    Wash all parts in a mild solvent and check all contact surfaces for burrs or other damage. (Also clean and inspect right-hand end of the handlebar.)

4.    Lubricate all contact surfaces with a light coat of lithium soap base grease and reassemble.


Tighten the housing screws evenly to maintain an even gap between the two halves.

5. Check for smooth throttle operation and quick spring return when released and make certain that the housing does not rotate on the handlebar.


Shaft and Rear Drive



Refer to "CHAPTER 3". for the middle gear.

The following special tools are not available but can be constructed for the final gear

disassembly and assembly:



A. Troubleshooting

1. The following conditions may indicate damaged shaft drive components:



Possible damaged areas

1.  A pronounced hesitation or "jerky" movement during acceleration, deceleration, or sustained speed. (This must not be confused with engine surging or transmission characteristics).

2.  A "rolling rumble" noticeable at low speed; a high-pitched whine; a "clunk" from a shaft drive component or area.

A.  Damage to bearings.

B.  Improper gear lash.

C.  Gear tooth damage.

D.  Drive flange/universal joint bolts loose.

3. A locked-up condition of the shaft drive mechanism; no power transmitted from engine to rear wheel.

E.  Broken drive-shaft.

F.  Disconnected flange/universal joint connection.

G. Broken gear teeth.

H. Seizure due to lack of lubrication.

I. Small foreign object lodged between moving parts.



Damage areas A, B, and C above may be extremely difficult to diagnose. The symptoms are quite subtle and difficult to distinguish from normal motorcycle operating noise. If there is reason to believe component(s) are damaged, remove component(s) for specific inspection.

2. Inspection Notes:

a.   During coasting, accelerating or decelerating, the "rolling rumble" will increase with rear wheel speed, not engine or transmission gear speeds. However, such noise may also be due to wheel bearings.

b.   Noise that varies with acceleration and deceleration: Following incorrect reassembly, a condition of too-little gear lash may produce a whine during deceleration.


Too-little gear lash is extremely destructive to gear teeth. If a test ride following reassembly indicates this condition, stop riding immediately to minimize damage to gears.

c. A slight "thunk" must be distinguished from normal motorcycle operation. It will be most noticeable at low speed and could indicate broken gear teeth.


If broken gear teeth are suspected, stop riding immediately. This condition could lead to locking-up of the shaft drive assembly and result in harm to a rider.

d. If the drive flange/universal joint bolts are slightly loose, a "clunk" may be felt when slowly taking off, or when changing from slow acceleration to slow deceleration. At high speed this will result in vibration.


Do not continue riding a motorcycle suspected of having loose flange/universal joint bolts. The components may break, causing injury to a rider.

3. Troubleshooting Chart

Where Basic Conditions "a" and "b" above exist, consider the following Chart:

Elevate and spin front wheel. Feel for wheel bearing damage.


Replace wheel bearing.

(See CHAPTER 5 "Front wheel")


Check rear wheel.

Feel for bearing damage.



Rear wheel bearings and shaft drive bearings probably not damaged.

Repeat test or remove individual components.


Remove rear wheel. Check for wheel bearing damage.


Replace rear wheel bearing. (See "Rear Wheel" section in this chapter.)


Remove drive shaft components.

4. Oil Leak Inspection

If a shaft drive component is suspected of leaking oil, first thoroughly clean the entire motorcycle. The apparent location of an oil leak on a dusty motorcycle may be misleading. Dry the motorcycle and apply a leak-localizing compound or a dry-powder spray that will limit the flow of any leaking oil. Operate the motorcycle prepared in this way for the distance necessary to precisely locate the leak. There are the possibilities that a component housing may have been damaged by road debris or an accident, or a gasket or seal may be cracked or broken. However, on new or nearly new motorcycle an apparent oil leak may be the result of a rust-preventive coating or excess assembly lubrication of seals. Always clean the motorcycle and recheck the suspected location of any apparent leakage.

5. Checking Drained Oil

Whenever a problem is suspected in either the middle or final gear assemblies, drain and inspect the oil. Metal particles on the drain plug or in the oil could indicate a bearing seizure or other problem in the component. However, a small amount of metal particles in the oil is normal.

B.   Final Gear Removal

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1. Remove:
• Rear axle
• Rear wheel
(see "Rear Wheel" section in this chapter).
• Left shock absorber
• Nut 1
• Final gear assembly 2

2.    Remove the 4 nuts holding the Final Drive unit to the swing arm.

3.    Remove the final gear assembly.

C.   Gear Lash Check and Adjustment

1.    Secure the gear case in a vice or other support.

2.    Remove one nut from the final gear case stud bolt. Install the gear holder (special tool) over the ring gear surface and stud bolt. Tighten the holder to stud bolt with a nut.

1. Final gear holding tool

3. Install the final gear lash measurement tool on the gear coupling.

1. Gear lash measurement tool (Final gear)

4. Mount a dial gauge against the lash measurement tool at the scribed mark (60 mm, 2.36 in from the center of the shaft).

5. Use the special wrench to gently rotate the gear coupling back and forth. Note the lash measurement on the dial gauge.

Final gear lash:

When using the measurement tool: 0.25 - 0.50 mm (0.010-0.020 in) .
Actual gear lash on the final gear teeth: 0.1 ~ 0.2 mm (0.004 ~ 0.008 in).

1. Middle and final gear holding tool

6. If the gear lash exceeds the specified limits, adjust as follows:

a.   To reduce gear lash, increase the ring gear shim.

b.   To increase gear lash, reduce ring gear shim.

1. Ring gear shim

c. If it is necessary to increase the ring gear shim by more than 0.1 mm reduce the thrust washer thickness by 0.1 mm for each 0.1 mm of ring gear shim increase and if it is necessary to reduce shim by more than 0.1 mm, reverse above procedure.

D. Final Gear Disassembly

1.    Remove the nuts and bolts holding the bearing housing.

2.    Remove the ring gear assembly and thrust washer from the final gear case.

3. Remove the self-locking nut from drive pinion by using the holding tool (special tool) and remove the coupling.

1. Middle and final gear holding tool

4. Remove the drive pinion bearing retainer with the retainer remover (special tool).


The drive pinion bearing retainer nut is left hand threads. Turn the retainer nut clockwise to loosen.

1. Drive pinion bearing retainer remover

5. Remove the drive pinion and bearing with the slide hammer and adapter (special tool).

1. Slide hammer    2. Adapter


This drive pinion removal should be performed only if gearing replacement is necessary. Do not re-use bearings or races after removal.

6. Remove the guide collar, oil seal, and roller bearing from the main housing by using the press tool No. 1 (special tool) and a press. Use an appropriate supports for the main housing during this operation. The roller bearing may be re-used if undamaged. Do not re-use oil seal.

Rear drive pinion roller bearing; removal of this bearing is difficult and seldom necessary. Heat the bare housing to 150°C (302°F). Use an appropriately shaped punch to remove the roller bearing outer race. Remove the inner race from the drive pinion.

E. Final Gear Reassembly

1.    Install the new rear drive pinion roller bearing. Heat the bare bearing to 150°C (302°F) and use an appropriately adapter to install the roller bearing outer race. Install the inner race onto the drive pinion.

2.    Using the press tool No. 2 (special tool) and a press, install the guide collet, new oil seal, and roller bearing into the main housing in that order.


The removed roller bearing can be used if undamaged; however, we recommend replacement with a new one.

3. Final drive/ring gear positioning 


When the following part(s) is replaced with new one(s), gear positioning is necessary: a. Final gear case, b. Ring gear bearing housing, C. Bearing(s)

a. The shim thickness "A" necessary for the drive pinion gear positioning can be calculated from the information found on the final gear case and on the drive gear end.

1. Size number

To fined shim thickness "A" use the


A = a -b


a = a numeral (usually a decimal number) on the gear near the tooth and either added to or detracted from the nominal size "84". 

b = a numeral on the gear case appearing as a whole figure (ie. 83.50).


1)    If the pinion gear is marked "+01"....."a" is 84.01.

2)    If the gear case is marked "83.50".

A = 84.01 - 83.50 A = 0.51

Then the necessary shim thickness is 0.51mm.

Shim sizes are supplied in the following thicknesses:

0.15 mm, 0.30 mm, 0.40 mm, 0.50 mm, 0.60 mm.

Because the shims can only be selected in 0.05 mm increments the following chart should be used when encountering last digits that are not 5 or zero (0):

Last digits




3, 4, 5, 6, 7




b. The shim thickness "B" necessary for the ring gear positioning can be calculated from the information found on the final gear case, ring gear, and bearing.

To find shim, thickness "B" use the


B = c + d-(e + f)


c= a numeral on the gear case appearing as a whole figure (ie. 45.52)

d = a numeral (usually a decimal number) on the outside of the ring gear bearing housing and added to the nominal size "3".

e= a numeral (usually a decimal number) on the inside of the ring gear and; either added to or detracted from the nominal size "35.40".

f = a bearing thickness (considered constant)

Distance "f" = 13.00 mm


1)    If the gear case is marked "45.52".

2)   If the ring gear bearing housing is marked "35"....."d" is 3.35.

3)    If the ring gear is marked "+01" ..... "e" is 35.40 + 0.01 = 35.41.

4)   "f" is 13.00.

B = c + d-(e + f)

B = 45.52 + 3.35 - (35.41 + 13.00)

B = 48.87- (48.41)

B = 0.46

Then the necessary shim thickness is

0.41 mm.


Use the chart for the drive pinion shim to select the ring gear shim size.

4. Install the drive pinion gear with the proper size of shim(s) and secure it with the bearing retainer nut with the drive pinion bearing retainer remover (special tool).


The bearing retainer nut is left hand threads; turn the nut to counterclockwise to tighten.

Tightening torque: 11 m-kg (80 ft-lb)

Install the ring gear assembly without the thrust washer. Adjust the gear lash (refer to "C. Gear lash check and adjustment).

Place four pieces of "PLASTIGAGE" between the originally fitted thrust washer and ring gear. Install the gear case onto the ring gear assembly and tighten the nuts and bolts with the specified torque.

Tightening torque;

Bolt/Nut......... 2.3 m-kg

(16.6 fMb)


Do not turn the drive pinion/ring gear when measuring clearance with "PLASTIGAGE".

8. Remove the ring gear assembly and determine the clearance by measuring the width of the flattened "PLASTIGAGE".


Ring gear thrust clearance. 0.1 ~ 0.2 mm

9. If the clearance exceeds the specification above, replace the thrust washer to obtain the proper clearance.


A. Removal

1.    Remove the rear wheel. See "REAR WHEEL A. Removal" in this chapter.

2.    Remove the final gear case assembly.

3.    Remove the drive shaft. See "SWING ARM removal" in this chapter.

4.   To remove the universal joint, it is necessary to remove the swing arm. Remove the universal joint assembly.

B,   Inspection

1. Drive shaft

Inspect the shaft splines for wear and/or damage. If excessive, replace the drive shaft.


When installing the drive shaft, lubricate splines with molybdenum di-sulfide grease.

2. Universal joint 

a. There should be no noticeable play in the universal joint bearings. If there is any play in the bearing, replace the universal joint assembly.

b. Move the universal joint up and down and from side to side. The universal joint should move smoothly. Without tightness, binding or rough spots that could indicate damaged bearings. If damaged, replace the universal joint assembly.

C. Reinstallation

When installing the drive shaft and the universal joint, reverse the removal procedure. Note the following points:

1.    Lubricate the shaft splines with molybdenum di-sulfide grease.

2.    Tighten the universal joint securing bolts and final gear case securing nuts with the specified torque:

Final gear case: 4.2 m-kg (30.4 ft-lb) Universal joint: 4.4 m-kg (31.8 ft-lb)




Wiring Diagram


Electric Starting System



The starting circuit on this model consists of the starter motor, starter relay, and the starting-circuit cut-off relay. If the engine stop switch and the main switch are both on, the starter motor can operate only if:

a.   The transmission is in neutral (the neutral switch is on).

or if

b.  The clutch lever is pulled to the handlebar (the clutch switch is on) and the sidestand is up (the sidestand switch is on).

The starting-circuit cut-off relay prevents the starter from operating when neither of these conditions has been met. In this instance, the starting-circuit cut-off relay is off so current cannot reach the starter motor. When one or both of the above conditions have been met, however, the starting-circuit cut-off relay is on, and the engine can be started by pressing the starter switch.

A. Sidestand Relay

The sidestand relay operates by shorting the TCI control current. When the sidestand is down, the sidestand relay is closed, and the TCI control current is grounded through the sidestand relay. Thus, the engine will not run with the sidestand down unless the transmission is in neutral.



B. Starter Motor

1.    Removal (see CHAPTER 3. "ENGINE DISASSEMBLY")

2.    Inspection and repair

a.   Check the outer surface of the commutator. If its surface is dirty, clean with # 600 grit sand paper.

b.  The mica insulation between commutator segments should be 0.4 ~ 0.8 mm (0.02 ~ 0.03 in) below the segment level. If not, scrape to proper limits with appropriately shaped tool. (A hack saw blade can be ground to fit.)


Mica insulation of commutator must be undercut to ensure proper operation of commutator.

c. The starter's armature coil should be checked with an ohm meter for insulation breakdown (shorting to each other or to ground) and for continuity. Reference figure is given below.

Coil resistance: Armature coil: 0.014Ω at 20°C (68°F)

d.   Check the front and rear cover bearings for damage. If damaged, the starter assembly must be replaced.

e.   Check brush length. Replace brush if at, or near, limits.

Minimum brush length: 8.5 mm (0.33 in)

f. Check brush spring pressure. Compare it with a new spring. Replace the old spring if it is weak.

C. Starter Relay Switch

1. Inspection

a.   Disconnect starter cable at the relay.

b.   Connect pocket tester leads to the relay terminals (ohms x 1 scale).

c.   Turn ignition to "ON" position, engine stop switch to "RUN" and change lever to "NEUTRAL".

d.   Push the starter button. The relay should click once and the scale should read zero if it does not read zero, the relay must be replaced.

1. Battery lead wire (+)

2. Starter motor lead wire

e. If the relay does not click, check the wires from the starter button and from the battery (red/white, blue/white). Turn the ignition off. Use (ohms x 1) scale on tester. The resistance between these wires should be no more than 3.5Ω. If there is more resistance, the relay should be replaced.

Charging System


A. Circuit Diagram

Above circuit diagram shows charging circuit in wiring diagram.

B. A.C. Generator

1. Checking method.

a.  Connect D.C. voltmeter to the battery terminals.

b.  Start engine.

c.   Accelerate engine to approximately 2,000 r/min or more and check generated voltage.

Generated voltage: 14.5± 0.3V

d. If the indicated voltage cannot be reached, then perform the tests in step 2.


Never disconnect wires from the battery while the generator is in operation. If the battery is disconnected, the voltage across the generator terminals will increase, damaging the semiconductors.

2. Resistance test of field coil and stator coil.

Check the resistance between terminals. If resistance is out of specification, coil is broken. Check the coil connections. If the coil connections are good, then the coil is broken inside and it should be replaced.

Field coil resistance:


4.0Ω ± 10% at 20°C (68°F)

Stator coil resistance


0.46Ω ± 10% at 20°C (68°F)

C. Voltage Regulator

The IC Voltage Regulator is a small and, normally, very reliable component. Due to its construction, it is lightweight and free from the wear and misadjustment associated with mechanical voltage regulators. If the following inspection reveals that the regulator is faulty, it cannot be adjusted and must be replaced. 

1. Checking IC Voltage Regulator

a.   Remove the seat.

b.   Remove the left side cover.

c.  Measure the specific gravity of the battery fluid. If it is less than 1.260, remove the battery and recharge until it is more than 1.260. (See page 124 for charging procedures)

d.  Check the battery terminals and couplers for looseness.

e.  Connect two Yamaha pocket testers to the regulator coupler as illustrated.


Be careful not to let the tester leads short circuit when connecting them to the regulator snap connector leads.

f.   Turn the main switch on. Make sure that V2 is less than 1.8V.


Do not turn on lights or signals.

g.   Make sure that V2 gradually increases up to 9 ~ 11V when the engine is started and its revolutions go up.

h. Make sure that Vi maintains the level of 14.2 ~ 14.8V even when engine revolutions increase.

i. If these levels are not maintained, the regulator is defective and must be replaced.

2. Checking the silicon rectifier a. Check the silicon rectifier as specified using the Yamaha pocket tester.



Pocket tester connecting point



(element shorted)




(+) (red)





































































0 : Continuity

x : Discontinuity ()

b. Even if only one of the elements is broken, replace the entire assembly.


The silicon rectifier can be damaged if subjected to overcharging. Special care should be taken to avoid a short circuit and/or incorrect connection of the positive and negative leads at the battery. Never connect the rectifier directly to the battery to make a continuity check.

Ignition System

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IGNITION SYSTEM A. Circuit Diagram

Above circuit diagram shows only ignition circuit in wiring diagram.

B.  Description

This model is equipped with a battery operated, fully transistorized breakerless ignition system. By using magnetic pick-up coils the need for contact breaker points is eliminated. This adds to the dependability of the system by eliminating frequent cleaning and adjustment of points and ignition timing. This T.C.I. (Transistor Control Ignition) unit incorporates an automatic advance circuit controlled by signals generated by the pick-up coil. This adds to the dependability of the system by eliminating the mechanical advancer. This T.C.I, system consists of two main units; a pick-up unit and ignitor unit.

C.   Operation

The T.C.I, functions on the same principle as a conventional D.C. ignition system with the exception of using magnetic pick-up coils and a transistor control box (T.C.I.) in place of contact breaker points.

1. Pick-up unit

1. Pick-up coils

This unit consists of two pick-up coils and a magneto mounted on the crank-case (L.H.). When the reluctor (timing plate) projection passes the pick-up coil, the two signals are generated at the pickup coil and transmitted to the ignitor unit as a signal. The full ignition advance is determined by the width of the reluctor (timing plate) projection.

2- Ignitor unit

This unit has such functions of wave form, duty control, switching, electrical ignition advance, and etc. The ignition timing is advanced electrically using two signals from the pick-up coil. The duty control circuit is provided to control the on time period of the primary ignition current to reduce the electrical consumption. This unit also incorporates a protective circuit for the ignition coil. If the ignition switch is turned on and the crankshaft is not turned, the protective circuit stops current flow to the primary coil within a few seconds. When the crankshaft is turned over, the current is turned on again by the signals generated by the pick-up coils.


Do not run the engine without any spark plug cap(s) in place. Due to the high secondary voltage, it is possible to damage the internal insulation of the secondary coil.

D. Troubleshooting/Inspection

1. The entire ignition system can be checked for misfire and weak spark using the Electro Tester. If the ignition system will fire across a sufficient gap, the entire ignition system can be considered good. If not, proceed with individual component tests until the problem is found.

a. Warm up engine thoroughly so that all electrical components are at operating temperature.

b. Stop the engine and connect the tester as shown.

c. Start the engine and increase the spark gap until misfire occurs. (Test at various r/min between idle and red line.)

Minimum spark gap: 6 mm (0.24 in)


Do not run engine in neutral above 6,000 r/min for more than 1 or 2 seconds.

2. If the ignition system should become inoperative, the following troubleshooting aids will be useful.

Check entire ignition for connections


Poor connection



Check battery for voltage and specific gravity


Low voltage & specific gravity

Recharge battery


Check fuse and fuse connections --------------->
Weak connection or open circuit
Correct connection or replace fuse


Check resistance of ignition coil {primary and secondary) 
Primary: 2.5 Ω ± 10% at 20°C (68°F) 
Secondary: 11KΩ ± 20% at 20°C(68 F)


If other than specified

Replace ignition coil


Check pick-up coils for resistance Pick-up coil: 700 Ω ± 20% at 20°C (68°F)


If other than specified

Replace pick-up coil assembly


TCI unit is faulty, replace unit    


3. Ignition coil 

a. Coil spark gap test.

1)   Remove the fuel tank and disconnect the ignition coil from wire harness and spark plugs.

2)   Connect the Electro Tester as shown.

3)  Connect fully charged battery to tester.

4)  Turn on spark gap switch and the increase gap to maximum unless misfire occurs first.

Minimum spark gap: 6 mm (0.24 in)

b. Direct current resistance test. Use a pocket tester or equivalent ohmmeter to determine resistance and continuity of primary and secondary coil windings.

Standard value: Primary coil resistance:

2.5 ± 10% at 20°C (68°F) 

Secondary coil resistance:

11 KΩ  ± 20% at 20% (68°F)

Primary coil check

Secondary coil check

4. Spark plug

The life of a spark plug and its discoloring vary according to the habits of the rider. At each periodic inspection, replace burned or fouled plugs with new ones of the specified type. It is actually economical to install new plugs often since it will tend to keep the engine in good condition and prevent excessive fuel consumption.

a.    Inspection

1)   Inspect and clean the spark plug every 4,000 km (2,500 mi) and replace after initial 13,000 km (8,000 mi).

2)   Clean the electrodes of carbon and adjust the electrode gap to the specification.

b.   Installation

Be sure to use the proper reach, type and electrode gap plug(s) as a replacement to

avoid overheating, fouling or piston damage.


BP7ES (NGK) or W22EP (ND) Electrode gap:

0.7 - 0.8 mm (0.028 - 0.031 in) Tightening torque:

2.0 m-kg (14.5 ft-lb)

Lighting System


A. Circuit Diagram

Above circuit diagram shows only lighting circuit in wiring diagram.

B. Lighting Tests and Checks

The battery provides power for operation of the headlight, taillight, and meter lights. If none of the above operates, always check battery voltage before proceeding further. Low battery voltage indicates either a faulty battery, low battery water, or a defective charging system. See page 113 "CHARGING SYSTEM" for checks of battery and charging system. Also check fuse condition. Replace any "open" fuses. There are individual fuses for various circuits (see complete Circuit Diagram).


Check the headlight bulb first before performing the following check.

1. Headlight check NOTE:

When the engine is started, the headlight and meter lights come on automatically and the lights stay on until the main switch is turned to "OFF" even if the engine stalls.


Check for voltage on "W" wire to safety relay

No voltage

Check AC generator, diode, or wiring circuit

Voltage OK

Check for battery voltage (12V) on "R/Y" wire to headlight relay

No voltage

Check fuse "Head or wiring circuit

Voltage OK

Check for battery voltage (12V) on "L/B" wire from headlight relay

No voltage

Replace headlight relay



Check for battery voltage at dimmer switch terminal

No voltage

Dimmer switch defective

Voltage OK

Check for battery voltage at headlight high beam or low beam terminal

No voltage

Open or poor connection between headlight and dimmer switch terminal

Voltage OK

Poor ground or poor connection of headlight wiring

2. Taillight does not work: 

a. Check bulbb

b. Check for 12V on blue wire.

c. Check for ground on black wire to tail/brake light and/or license light assembly.



A. Circuit Diagram

Above circuit diagram shows only signal circuit in wiring diagram.

B. Signal System Tests and Checks

The battery provides power for operation of the horn, brake light, indicator lights and flasher light. If none of the above operates, always check battery voltage before proceeding further. Low battery voltage indicates either a faulty battery, low battery water, or a defective charging system. See page 113 "CHARGING SYSTEM" for checks of battery and charging system. Also check fuse condition. Replace any "open" fuses. There are individual fuses for various circuits (see complete Circuit Diagram).

1.    Horn does not work:

a.   Check for 12V on brown wire to horn.

b.   Check for good grounding of horn (pink wire) when horn button is pressed.

2.    Brake light does not work:

a.   Check bulb.

b.   Check for 12V on yellow wire to brake light.

c.   Check for 12V on brown wire to each brake light switch (front brake and rear brake switches).

3.    Flasher light(s) do not work:

a.   Check bulb.

b.   Right circuit:

1)   Check for 12V on dark green wire to light.

2)  Check for ground on black wire to light assembly.

c.   Left circuit:

1)  Check for 12V on dark brown wire to light.

2)  Check for ground on black wire to light assembly.

d.   Right and left circuits do not work:

1)   Check for 12V on brown/white wire to flasher switch on left handlebar.

2)  Check for 12V on brown wire to flasher relay.

3)   Replace flasher relay.

4)   Replace flasher switch.

e.   Check flasher self-canceling system. (Refer to flasher self-canceling system.)

4. Neutral light does not work:

a.   Check bulb.

b.   Check for 12V on sky blue wire to neutral switch.

c.   Replace neutral switch.

6. Oil level warning light does not work:

a.   Connect oil level switch (black/red wire) to ground. If light comes on, check for proper oil level.

b.   If oil level is correct, replace oil level switch.

C. Self-Canceling Flasher System

1.    Description:

The self-canceling flasher system turns off the turn signal after a period of time or distance involved in turning or changing lanes. Generally, the signal will cancel after either 10 seconds, or 150 meters (490 feet), whichever is greater. At very low speed, the function is determined by distance; at high speed, especially when changing speeds the canceling determination is a combination of both times and distance.

2.    Operation:

The handlebar switch has three positions: L (left), OFF, and R (right). The switch lever will return to the "OFF" position after being pushed to L or R, but the signal will function. By pushing the lever in, the signal may be cancelled manually.

3.    Inspection

If the flasher self-canceling system should become inoperative, proceed as follows:

a. Pull of the 6-pin connector from the flasher canceling unit, and operate the handlebar switch, if the signal operates normally in L, R, and OFF, the following are in good condition.

1)   Flasher unit

2)   Bulb

3)   Lighting circuit

4)   Handlebar switch light circuit

If (1) through (4) are in good condition, the following may be faulty:

1)   Flasher canceling unit.

2)   Handlebar switch reset circuit.

3)   Speedometer sensor circuit.

b.   Pull off the 6-pin connector from the flasher canceling unit, and connect a tester (ohms x 100 range) across the white/green and the black lead wires on the wire harness side. Turn the speedometer shaft. If the tester needle swing back and forth between 0 and , the speedometer sensor circuit is in good condition. If not, the sensor to wire harness may be inoperative.

c.    Pull the 6-pin connector from the flasher canceling unit. Check if there is continuity between the yellow/red lead wire on the wire harness side and the chassis.

Flasher switch OFF:  
Flasher switch L or R: 0 ohms

If the tester needle does not swing as indicated above, check the handlebar switch circuit and wire harness.

d.   If no defect is found with the above three check-ups and the flasher canceling system is still inoperative, replace the flasher canceling unit.

e.    If the signal flashes only when the handlebar switch lever is turned to L or R and it turns off immediately when the handlebar switch lever returns to center, replace the flasher canceling unit.

D. Switches

Switches may be checked for continuity with a pocket tester on the "ohm x 1" position. 1. Main switch

Switch Position

Wire Color
















P (parking)


------ ----0

2. "ENGINE STOP" Switch


Wire Color










3. "START" switch

Button Position

Wire Color









4. "LIGHTS" (Dimmer) switch

Switch Position

Wire Color








0--- --O












5. "TURN" switch



Wire Color












L > N






N > Push






R > N












6. "HORN" Switch

Button Position

Wire Color









E. Battery

1. Checking

If the battery shows the following defects, it should be replaced.

a.   The battery voltage will not rise to a specific value or no gassing occurs in any cell even after many hours of charging.

b.   Sulfation of one or more cells is indicated by the plates turning white or an accumulation of material in the bottom of the cell.

c.   Specific gravity readings after a long slow charge indicate a cell to be lower than any others.

d.   Warpage or buckling of plates or insulators is evident.


Battery fluid is poisonous and dangerous, causing severe burns, etc. Contains sulfuric acid. Avoid contact with skin, eyes or clothing.


EXTERNAL-FLUSH with water.

INTERNAL-Drink large quantities of water or milk. Follow with milk of magnesia, beaten egg or vegetable oil. Call physician immediately.

Eyes: Flush with water for 15 minutes and get prompt medical attention. 

Batteries produce explosive gases. Keep sparks, flame, cigarettes, etc., away. Ventilate when charging or using in enclosed space. Always shield eyes when working near batteries.


2.    The service life of a battery is usually 2 to 3 years, but lack of care as described below will shorten the life of the battery.

a.   Negligence in keeping battery topped off with distilled water.

b.   Battery being left discharged.

c.   Over-charging with heavy charge.

d.   Freezing.

e.   Filling with water or sulfuric acid containing impurities.

f.    Improper charging voltage or current on new battery.

3.    If the motorcycle is not to be used for a long time, remove the battery and have it stored. The following instructions should be observed:

a.   Recharge the battery periodically.

b.   Store the battery in a cool, dry place.

c.    Recharge the battery before reinstallation.




Specific gravity: 1.280

Initial charging current

1.2 amp for 10 hours (new battery)

Recharging current

10 hours (or until specific gravity reaches 1.280)

Refill fluid

Distilled water (to maximum level line)

Refill period

Check once per month (or more often, required)

Chapter 7, Appendices



General Specifications



Basic color 


Overall length

Overall width

Overall height

Seat height


Minimum ground clearance

Caster (steering head angle)


Black Blue or New Ruby Red


2,165 mm (85.2 in)

860 mm (33.9 in) 

1,180 mm (46.5 in)

750 mm (29.5 in) 

1,445 mm (56.9 in)

150 mm ( 5.9 in) 


124 mm (4.88 in)

Weight: Net

203 kg (447 lb)

Engine: Type

Bore x stroke x cylinders 


Compression ratio

D.O.H.C. air-cooled, gasoline

63.0 x 52.4 mm x 4 (2.480 x 2.063 in x 4)

653 cc (39.85 cu. in)

9.2 : 1


Lubrication system 

Delivery pump type


Pressure lubricated, wet sump 





Rated venturi size



HSC32, constant velocity

32 mm (1.26 in)

Air filter:

Dry type element

Spark plug

Battery ignition (Full transistor ignition) 
BP7ES(NGK) or W22EP (ND)



Manufacture, I.D. No. 

Maximum output 

Battery type 

Battery dimensions 


Regulating voltage (No. load)


Three-phase, regulated alternator

 HITACHI, LD119-08 

14V 19A 


80 x 160 x 134 mm (3.15 x 6.30 x 5.28 in)

 S8534, I.C. type, full wave 

14.2 - 14.8V


Electric starter

Primary drive: 





Spur gear 




Wet, multiple disc




Constant mesh, 5-speed drum shifter



Teeth, ratio 1st 





35/16 2.187 

30/20 1.500 

30/26 1.152 

28/30 0.933 

26/32 0.812

Secondary drive:


Transmission output:
Type, teeth, ratio 

Middle gear case:
Type, teeth, ratio 

Final gear case:
Type, teeth, ratio


Shaft drive

Spur gear, 49/36, 1.361 1

Bevel gear, 19/18, 1.055

Bevel gear, 32/11,2.909



Front (type, travel)
Rear (type, travel} 




Fuel tank: 


Tubular steel double cradle

Telescopic fork 150 mm (5.91 in) 
Swing arm, 80 mm (3.15 in)


130/90-16 67H, Tubeless

Single hydraulic disc
Drum brake

13 Lit (3.4 US. gal)
3.4 Lit (0.8 US. gal)

MT1.85 x 19, Cast Aluminum
MT3.00 x 16, Cast Aluminum

Maintenance Specifications

1. Engine

Engine oil capacity:

Total amount

Oil and filter change

Oil change Recommended lubricant:

If temperature does not go below 5"C (40 F)

If temperature does not go above 15~C (60 F)

3,200 cc (3.4 US. qt) 

2,650 cc (2.8 US. qt) 

2,350 cc (2.5 US. qt)


SAE 20W/40SE motor oil 

SAE 10W/30SE motor oil

Cranking pressure (at seal level): 

Maximum difference between cylinders:

11 kg/cm2 (156 psi) 

1 kg/cm2 (14 psi)



Standard size

Wear limit



36.80 mm (1.449 in)

28.0 mm (1.102 in)

8.50 mm (0.335 in)

36.65 mm (1.443 in) 

27.85 mm (1.096 in)




35.80 mm (1.449 in) 

28.0 mm (1.102 in)

7.8 mm (0.307 in)

35.65 mm (1.404 in) 

27.85 mm (1.096 in)


Camshaft bearing surface diameter:    

24.967 - 24.980 mm (0.9830 ~ 0.9835 in)

Camshaft-to-cap clearance:

Standard                     0.020- 0.054 mm (0.0008-0.0021 in)

Maximum                    0.160 mm (0.006 in)

Camshaft runout limit   0.1 mm (0.004 in)





Free length

35.9 mm (1.413 in)

39.5 mm (1.555 in)

Spring rate

2.36 kg/mm (132.2 lb/in)

4.58 kg/mm (256.5 lb/in)

Installed length (valve closed)

31.0 mm (1.220 in)

34.0 mm (1.339 in)

Installed pressure

(valve closed)

9.0 kg (19.8 lb)

19.1 kg (42.1 lb)

Compressed length (valve open)

IN: 22.8 mm (0.898 in) 
EX:23.5 mm (0.925 in)

IN: 25.8mm(1.016 in) EX:26.5mm(1.043 in)

Wire diameter

2.8 mm (0.110 in)

3.9 mm (0.154 in)

Number of windings



Winding O.D.

20.6 +°*3 mm (0.811**012 in)

29.4_° mm (1.157^0°012 in)

Valve stem run-out maximum:                   0.03 mm (0.0012 in)

Valve seat width standard/maximum :     1.0 mm (0.039 in)/2.0 mm (0.080 in)


Clearance (Cold engine)

0.11 -0.15 mm (0.004- 0.006 in)

"A" head diameter

33 ± 0.1 mm (1.2992 ± 0.0039 in)

"B" face width

2.3 mm (0.0906 in)

"C" seat width

1.0 ± 0.1 mm (0.0394 ± 0.0039 in)

"D" margin thickness (minimum)

1.2 ±0.2 mm (0.0472 ±0.0079 in)

Stem diameter (O.D.)


7-0.025 mm

tn 07RR -0.0004 . . (0>2756 -0.0010 m)

Guide diameter (|.D.)

-,+0.012 ' q mm

(0.2756 +°000B in)

Stem-to-guide clearance

0.010 ~0.037mm (0.0004 ~ 0.0015 in)


Clearance (Cold engine)

0.16~ 0.20mm (0.006-0.008 in)

"A" head diameter

28 ± 0.1 mm (1.2205 ±0.0039 in)

"B"face width

2.3 mm (0.0905 in)

"C" seal width

1.0 ± 0.1 mm (0.0394 ± 0.0039 in)

"D" margin thickness (minimum)

1.0 ±0.2 mm (0.0392 ± 0.0079 in)

Stem diameter (O.D.)

 7  -0.025 mm

 (0.2756  -0.0010 in)

Guide diameter (I.D.)

7  +0.012 mm

 (0.2756  -0.0005 in)

Stem-to-guide clearance

0.025 ~ 0.052 mm 
(0.0010 ~ 0.0020 in)


Cylinder and piston:

Cylinder material 

Cylinder liner 

Bore size: 
Wear limit 

Cylinder taper limit 

Cylinder out-of-round limit 

Piston clearance: 


Piston weight (include rings, pin and clips)

Aluminum alloy

Pressed in; special cast iron

63.00 mm (2.4803 in)
63.10 mm (2.4843 in)

0.05 mm (0.0020 in)

0.01 mm (0.0004 in)

0.030 ~ 0.050 mm 
(0.0012- 0.0020 in)
0.1 mm (0.0039 in)

213 g (7.520oz)

Piston rings:








End gap (installed): standard

0.15-0.35 mm (0.0059 ~ 0.0138 in)

0.15-0.35 mm (0.0059 ~ 0.0138 in)

0.3-0.9 mm (0.0118 -0.035 in)


1.0 mm (0.0394 in)

1.0 mm (0.0394 in)

1.5 mm (0.0591 in)

Side clearance: standard

0.03-0.07 mm (0.0012 ~ 0.0028 in)

0.02-0.06 mm (0.008 -0.0024 in)



0.15 mm (0.0059 in)

0.15 mm (0.0059 in)



Crank journal/bearing oil clearance 

Main journal run-out (maximum)

0.040-0.064 mm (0.0016-0.0025 in) 

0.040 mm (0.0016 in)

Connecting rods



Rod bearing oil clearance

345 g (12.2 oz)

0.03 - 0.09 mm (0.0012-0.0035 in)

Oil pump:

Housing-to-outer rotor clearance 

Outer rotor-to-inner rotor clearance

0.09- 0.15 mm (0.0035- 0.0059 in) 

0.12 mm (0.005 in) or less


Friction plate:  
minimum thickness 

Clutch plate: 
warp limit 

Clutch spring: 
minimum length
spring rate 

Clutch lever freeplay (at lever pivot point)

3.0 mm (0.12 in)

2.8 mm (0.11 in) 

1.6 mm (0.063 in)

0.05 mm (0.0020 in) 

40.1 mm (1.579 in)

39.1 mm (1.539 in) 
1.184 kg/mm (66.3 lb/in) 

2- 3 mm (0.08-0.12 in)

Transmission shaft run-out maximum:

0.08 mm (0.0031 in)

Middle gear case lash:

0.1 - 0.2 mm (0.0039 - 0.0079 in)


2. Carburetion


Model I.D.No. 

Main jet' 

Needle jet 

Pilot jet 

Starter jet 

Jet needle



#  110 

0 3.2

#  40

# 40(0 0.9)


Fuel level

Pilot screw 

Air jet, Main 

Air jet, Pilot 

Throttle valve 

Float valve seat 

Engine idle speed

3±1 mm (0.118+0.039 in)


#  50

#  195

32 mm (1.26 in)

0 2.0

1,050 r/min

3.  Chassis                               *Total weight of accessories, etc. excepting motorcycle.

Wheels and tires:
Rim run-out: 

2.0 mm (0.079 in) 
2.0 mm (0.079 in)

Tire pressure (cold):



Up to 90 kq (198 lb) load*

90 kg (198 lb) -160 kg (353 lb) load*

160 kg (353 lb)~230 kg (507 lb) load*
                                         (maximum load)

High speed riding

Minimum tire tread depth

1.8 kg/cm2 (26 psi) 


2.0 kg/cm2 (28 psi) 

2.3 kg/cm2 (36 psi) 

0.8 mm (0.03 in)

2.0 kg/cm2 (28 psi) 

2.3 kg/cm2 (32 psi) 

2.8 kg/cm2 (40 psi) 

2.5 kg/cm2 (40 psi) 

0.8 mm (0.03 in)


Recommended fluid

Pad wear limit

Rear brake lining wear limit

Brake disc maximum deflection

Brake disc minimum thickness

Front brake free play (end of lever)

Rear brake free play (end of pedal)


DOT =3

6.5 mm (0.26 in)

2 mm (0.08 in)

0.15 mm (0.006 in)

3.5 mm (0.26 in)

5.0^ 8.0 mm (0.2-0.3 in)

20 ~ 30 mm (0.8 - 1.2 in)

Front forks


Spring free length

Spring preload length

Spring rate: 
     0 -100 mm (0~3.94 in)
     100-150 mm (3.94~5.91 in) 

Fork oil capacity leach side) 

Oil type

150 mm (5.91 in)

606 mm (23.86 in)

571 mm (22.48 in)

0.475 kg/mm (26.6 lb/in)
0.626 kg/mm (35.1 lb/in)

262 cc (9.24 oz)

Yamaha Fork Oil 10Wt or equivalent

Rear shock absorbers:

Spring free length

Spring preload length

Spring rate: 
     0 ~ 55 mm (0~ 2.17 in)
     55 -80 mm (2.17-3.15 in)


232.5 mm (9.15 in) 

216.5 mm (8.52 in) 

1.6 kg/mm (89.6 lb/in) 
2.2 kg/mm (123.2 lb/in) 

80 mm (3.15 in)

4. Electrical

Ignition timing retarded:          10°at 1,050 r/min

Ignition timing advance:

Spark plug: 

Electrode gap


0.7 - 0.8 mm (0.023 - 0.032 in)

Spark plug cap resistance:

5.0kft (No. 1,No.4), 10kft (No. 2, No. 3)

Pick up coil: Resistance

700ft ± 20%at20°C(68°F)

Ignition coil type: Spark gap

Primary resistance 

Secondary resistance


2.5 Ω± 10%at20°C(68oFj

11kΩ± 20% at 20°C (68°F)

Starter motor type:

Armature coil resistance 

Brush length: 

Brush spring pressure

Armature mica undercut

Nippon Denso ADB4D2

0.014Ω ± 6% at 20°C (68°F)

12.0 mm (0.472 in)
8.5 mm (0.33 in)

800 ± 150g (28.24 ± 5.30 oz)

0.6 mm (0.024 in)

Battery type: 

Charging rate

G.S. 12N12A-4A

1.2 Amps for 10 Hours

Generator type: 


Field (inner) coil resistance

 Stator (outer) coil resistance


14V-19A at 5,000 r/min 

4.0Ω ±10%at20oC(68°F)

 0.46 Ω ± 10% at 20°C (68°F)

Regulator type: 

Regulated voltage 

Allowable amperage

I.C. (S8534)

14.5 ± 0.3V 


Starter relay switch: 

Cut-in voltage




Tail/brake light: 

Flasher light: 

License light: 

Pilot lights:
High beam
Oil level 
Meter light


12V, 8W (3CP)/27W (32CP) 

12V, 27W(32CP) x4 

12V, 8W (3CP) x2

12V, 3.4W x 1 
12V, 3.4Wx 1 
12V,3.4W x 1 

Torque Values

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Tightening torque 
(Unit: m-kg)

Part to be tightened

Part name

Thread size


Tightening torque





Cylinder head


M10 P1.25




Apply oil.

Cylinder head cover


M6 P1.0





Spark plug








M8 P1.25




Cam chain case Front & Rear

Cam shaft cap


M6 P1.0




Tighten in 3-stages.

Cam sprocket


M7 P1.0





Cam chain tensioner adjustment lock nut


M8 P1.25





Cam chain tensioner adjustment lock bolt


M6 P1.0





Connecting rod


M7 P0.75





Generator (rotor)


M10 P1.25





Drain plug


M14 P1.5 M8 P1.25



4.3 1.6

31.0 11.6

Crankcase drain Middle gear case drain

Oil filter


M20 P1.5





Pump cover


M6 P1.0





Strainer cover


M6 P1.0






Flange Bolt

M8 P1.25 M6 P1.0

12 27

2.4 1.2

17.5 8.7


Clutch boss


M20 P1.0





Clutch spring screw


M6 P1.0





Change pedal


M6 P1.0





Neutral switch

M10 P1.25





Exhaust pipe


M6 P1.0






—Middle Gear —







Drive Shaft


M34 P1.5





Mount cover


M8 P1.25





Driven shaft


M14 P1.5




Use LOCKTITE: Stake.

Bearing cap

Flange Bolt

M8 PI.25





- Final Gear —

Drive shaft


M14 P1.5





Bearing housing

Flange Bolt

M10 P1.25





Bearing housing


M8 PI .25





Oil mount screw


M14 P1.5





Oil drain screw


M14 Pi .5





Bearing retainer

M65 P1.5




Left hand screw


Engine Mounting Bolt

Front, upper
Front, under





M10 P1.25

M10 P1.25

M12 P1.25









Part to be tightened

Part name

Thread size


Tightening torque




Engine Mounting Stay



M8 P1.25





Handle crown & Steering shaft



M14 P1.25 M8 P1.25



5.4 2.0

39.1 14.5


Handle crown & Inner tube

Nut cap

M8 P1.25





Handle crown & Handle holder


M8 P1.25





Front fork

Under bracket & Inner tube


M8 P1.25





Front wheel shaft

Nut Castle

M14 P1.5





Front wheel Axle pinch bolt

Nut self locking

M8 P1.25





Pivot shaft


M22 P1.5




Taper roller bearing

Rear wheel shaft

Nut castle

M14 P1.5





Rear shock absorber (Upper)

Nut cap

M10 P1.25





Rear shock absorber (Lower)

L Nut cap R Bolt

M10 P1.25







M10 P1.25





Tension bar & Brake plate


M8 P1.25





Tension bar & Rear arm


M8 P1.25





Camshaft lever & Camshaft


M6 P1.0





Disc brake section

Brake disc & Hub (Front)


M8 P1 .25




Lock washer

Master cylinder & Brake hose (Front)

Bolt union

M10 P 1.25





Brake hose & Joint

Bolt union

M10 P1.25





Caliper & Brake hose

Bolt union

M10 P1.25





Caliper & Front fork (Front)


M8 PI.25





Caliper bleed screw (Front)


M8 P1.25




Front fender


M8 P1.25





Master cylinder cap


M5 P0.8





Pivot shaft


M22 P1.5




Lock washer

Final gear & Rear arm


M10 P1.25





Cross Joint

Hexagon bolt with washer

M8 P1.25





Muffler bracket & Frame


M10 P1.25





Rear fender


M10 P1.25





Muffler bracket & Muffler


M10 P1.25





Master cylinder & Master cylinder bracket


M6 P1.0





General Torque Specifications This chart specifies torque for standard fasteners with standard I.S.O. pitch threads. Torque specifications for special components or assemblies are included in the applicable sections of this book. To avoid warpage, tighten multi-fastener assemblies in a criss-cross fashion, in progressive stages, until full torque is reached. Unless otherwise specified, torque specifications call for clean, dry threads. Components should be at room temperature.

A (Nut)



General torque specifications



10 mm

6 mm



12 mm

8 mm



14 mm

10 mm



17 mm

12 mm



19 mm

14 mm



22 mm

16 mm






















































cc (cm3)


oz (US liq)

cc (cm )


cu. m

lit (liter)


pt (US liq)

lit (liter)


qt (US liq)

lit (liter)


gal (US liq)







psi (lb/in2

Centigrade (°C) 9/5(°C) + 32 Fahrenheit (° F)



















































oz (US liq)


cc (cm )



cc "cm )

pt (US liq)


lit (liter)

qt (US liq)


lit (liter)

gal (US liq)


lit (liter)





psi (lb/in )



Fahrenheit (°C)


Centigrade (°F)




Meter-kilogram(s) (usually torque)






Kilogram(s) (1,000 grams)






Kilometer(s) per liter (fuel consumption)



Cubic centimeter(s) (cm3) (volume or capacity)



Kilogram(s) per millimeter (usually spring compression rate)



Kilogram(s) per square centimeter (pressure)

Consumer Information



The information presented represents results obtainable by skilled drivers under controlled road and vehicle conditions, and the information may not be correct under other conditions.


This figure indicates braking performance that can be met or exceeded by the vehicles to which it applies, without locking the wheels, under different conditions of loading and with partial failures of the braking system.


("Partial failure" information is not applicable and is not included)


This figure indicates passing times and distances that can be met or exceeded by the vehicles to which it applies, in the situations diagrammed below. The low-speed pass assumes an initial speed of 20 mph. and a limiting speed of 35 mph. This high-speed pass assumes an initial speed of 50 mph. and a limiting speed of 80 mph.




Low-speed pass ........................................ 353.0 feet: 7.15 seconds

High-speed pass ........................................ 883.4 feet: 8.4 seconds


Lubrication Diagrams

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Cable Routing

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Parts Illustrations







Middle Gear Damper


Final Gear / Driveshaft


Front Wheel


Rear Wheel


Front Brake




Middle Gear Damper


Electrical Component Locations

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Wiring Diagram

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Dark green



L/W :


Ch :


0 :



Brown /White

B :




Y/G :


Y :


P :


B/W :



Light green





G :



Red /White



W :




G/Y •



Sky blue





R :


L/G :


Y/B :