VALVE CLEARANCE ADJUSTMENT

1 Valve lifter 2 Pad 3 Retainer   4 Spring seat

Valve Clearance (Cold): 
Intake: 0.11 -0.20 mm (0.004- 0.008 in) 
Exhaust: 0.21- 0.30 mm (0.008- 0.012 in)

Measurement

1. Remove:
• Seat
• Fuel tank
• Horns
• Ignition coil mount bolts (1)

2.  Disconnect the spark plug caps

3. Remove:

• Ignition coils
• Spark plugs
• Cylinder head cover
• Left crankcase cover

4. Measure the valve clearance

NOTE:.
Be sure piston is at Top Dead Center (TDC) on compression stroke when measuring clearance.

Valve clearance measurement steps:

•Turn the crankshaft counterclockwise with a 19 mm (0.75 in) spanner.

NOTE:
Valve clearance must be measured when the engine is cool to the touch.

(1) Pickup coil mark

(2) TDC for No. 1 cylinder

(3) Firing range for the No. 1 cylinder

• Align the "T" mark (2) on the timing plate with the pickup coil mark (1) . When the "T" mark is aligned with the stationary pointer (2) . the piston is at top dead center (TDC).

• Measure the valve clearance using a Feeler Gauge (3).
• Record the measured amount if the clearance is incorrect.

Intake Valve (cold): 0.11- 0.20 mm (0.004- 0.008in)
Exhaust Valve (cold): 0.21- 0.30 mm (0.008- 0.012 in)

Measure valve clearance, in sequence, for Nos. 2, 4, and No. 3 cylinders.

Out of specification - Adjust clearance.

Firing Sequence: 1 -2-4-3

[A] Crankshaft counterclockwise turning angle. [Bl Cylinder [C] Combustion

Adjustment

1. Remove carburetors Refer to CHAPTER 3 "ENGINE REMOVAL".

2.  Loosen the cam chain tensioner end plug (1)

3.  Remove the cam chain tensioner (2)

4. Remove:

•Cam chain guide (Upper) (1) 
•Cam cap I3 (2)
•Cam cap E3 (3)
• Dowel pins

5. Remove:

•Cam chain sprocket bolts
•Cam caps
•Dowel pins

•Cam shafts (1)
•Cam chain sprockets (2)

NOTE:
Fasten safety wire to the cam chain to prevent it from falling into the crankcase.

6.  Remove:
• Valve lifter (1)
• Pad (2)

Note the installed pad number (3). Round off the value as required:

7.  Select the proper pad from the appropriate chart (next 2 pages, links below)

EXAMPLE:

Installed pad number = 175 (1.75 mm)

Rounded off digit = 175

NOTE:
Pads can only be selected in 0.05 mm (0.02 in) increments.

* Locate the "Rounded off Pad Number" on the chart, and then find the measured valve clearance. The point where these coordinates intersect is the new pad number.

NOTE:
Use the new pad number as a guide only as the number must be verified.

8. Install:
• Pad (1)
• Valve lifter (2)
• Cam shaft
• Cam chain sprocket

Refer to CHAPTER 3 "ENGINE ASSEMBLY"

9. Recheck the valve clearance.

If the clearance is incorrect, repeat all of the clearance adjustment steps until the proper clearance is obtained.

Assembly

1. Reverse removal steps.

Inspect the head cover gasket and replace it if damaged.

2. Tighten:
• Cylinder head cover bolts
• Fuel tank bolts

Head Cover Bolt: 10 Nm (1.0 m.kg, 7.2 ft-lb)

Fuel Tank Bolt: 10 Nm (1.0 m.kg, 7.2 ft-lb)

SPARK PLUG 

1. Remove spark plugs

2.  Inspect:

• Electrode (1) for wear/damage.
• Insulator color (2)

3.  Measure the plug gap (3) using a Wire Gauge or Feeler Gauge. Regap as reqired.

Plug Gap: 0.6 - 0.7 mm (0.024 - 0.028 in)

Clean the plug with a spark plug cleaner if necessary.

Standard Spark Plug: DR8ES-L (NGK) X24ESR-U (NIPPONDENSO)

Before installing a spark plug, clean the gasket surface and plug surface. 

4. Tighten Spark plug(s) to 17.5 Nm (1.75 m-kg, 12.5 ft-lb)

NOTE:
Finger-tighten the spark plug(s) before torquing to specification.

CRANKCASE VENTILATION SYSTEM

1. Inspect the crankcase ventilation hose (1).  Replace damaged hoses.

FUEL LINE

1. Inspect:

• Fuel hose (1)
• Vacuum hose (2)

 Replace damaged hoses.

INTAKE MANIFOLD

1.  Tighten:
• Carburetor clamps
• Carburetor joint bolts

2.  Inspect:

• Carburetor joint
• Gaskets 

  Replace if necessary.

EXHAUST SYSTEM

1.  Inspect:
•Exhaust pipe gasket(s) (1)
• Muffler clamp gasket(s) (2)

Damage > Replace.
Exhaust gas leakage > Repair.

2.  Tighten:
• Exhaust pipe bolts
• Muffler bolts

Exhaust Pipe Flange (3) :10 Nm(1.0m-kg, 7.2ft-b) 
Exhaust Pipe Clamp (4) :20 Nm (2.0 m-kg, 14 ft-lb) 
Exhaust Chamber Mount (5): 25 Nm (2.5 m-kg, 18 ft-lb) 
Muffler Clamp (6): 20 Nm (2.0 m-kg, 14 ft-lb) 
Muffler Bracket (7) 20 Nm (2.0 m-kg, 14 ft-lb)

IDLE SPEED

1. Adjust the idle speed. Warm up the engine and turn the throttle stop screw (1) to adjust.

Idle Speed:
1,050 ± 50 r/min

CARBURETOR SYNCHRONIZATION

Carburetor Adjustment

Carburetors must be set properly before synchronizing the carburetors.

NOTE:
Valve clearance must be set properly before synchronizing the carburetors.

1.  Remove:

• Seat

• Fuel tank

2.  Disconnect:

• Vacuum plugs (1)

• Vacuum hose (2)

3.  Install:

• Vacuum Gauge (90890-03094)(1)

• Suitable test fuel tank

4.  Start the engine and let it warm up.

5. Turn throttle stop screw (1) to adjust idle speed to 1,050 ± 50r/min.

6. Adjust carburetor synchronization

Carburetor synchronization adjustment steps:

•Synchronize the carburetor No. 1 to the carburetor No. 2 by turning the synchronizing screw "1" until the both gauge readings are the same.

•Rev. the engine for a fraction of a second, two or three times, and check the synchronization again.

Vacuum Pressure at Idle Speed: 24 kPa (180 mm Hg, 7.1 in Hg)

Vacuum Synchronous Difference: 0.7 kPa (5 mm Hg, 0.2 in Hg)

• Repeat the above steps to synchronize the carburetor No. 4 to the carburetor No.3 by turning the synchronizing screw " 3 " until the both gauge readings are the same.

• Repeat the same steps to synchronize No. 3 carburetor to No. 2 carburetor, then turn synchronizing screw " 2 " until both gauge readings are the same.

ENGINE OIL

At 5°C(40°F) or Higher:  Yamalube 4-Cycle Oil or SAE 20W40 Type SE Motor Oil

At15°C(60°F) or Lower: SAE 10W30 Type SE Motor Oil

Note:
recommended engine oil classification; API Service "SE", "SF" type or equivalent (e.g. "SF-SE", "SF-SE-CC", "SF-SE-SD" etc.)

Oil Level Measurement

1. Check the oil level. Add as required.

Oil level visual inspection steps:

•Place the motorcycle on its centerstand and warm up the engine for several minutes.

NOTE:
Position the motorcycle straight up when checking oil level, a slight tilt to the side can produce false readings.

• Stop the engine and visually check the oil level through the level window (1) .

(2) Maximum 
(3) Minimum

Oil Change (Without filter) 

1. Warm up the engine for several minutes, then place a receptacle under the engine.

2.  Remove: The oil filler cap

3.  Remove the drain plug (1) and drain the engine oil.

4. Replace and tighten the drain plug

Engine Drain Plug: 43 Nm (4.3 m-kg, 31 fMb)

5. Fill the crankcase with engine Oil: 2.5 L (2.2 Impqt, 2.6 US qt)

CAUTION:
Do not allow foreign material to enter the crank-case.

6. Install the filler cap

Oil Change (With filter) 

1. Warm up the engine and place a receptacle under the engine. 

2. Remove: 
• Oil filler cap 
• Drain plug 

Drain the engine oil.

3.      Remove:
•  Oil filter bolt (1)
•  Filter cover (2)

4.    Replace and tighten the drain plug

Engine Drain Plug:

43 Nm (4.3 m-kg, 31 ftlb)

5. Install:

•   Oil filter bolt 1

•   Spring 2

•   Washer 3

•  Oil filter (New) 4

•   O-ring 5 (x2, one on bolt, one on cover)

•   Oil filter assembly

NOTE:
•   Be sure the O-ring 5 is positioned properly.
•   Fit the filter cover projection into the crank-case cover slot.

6. Tighten the oil filter bolt

Oil Filter Bolt: 15 Nm (1.5 nvkg. 11 ftlb)

7. Fill the crankcase with Engine Oil: 2.8 L (2.5 imp qt, 3.0 US qt)

8. Install the oil filler cap

9.      Warm up the engine and check for oil leaks. Stop the engine instantly if leaking occurs.

10.   Check the oil level

Level low — Add sufficient oil.

COOLANT

Recommended Coolant:

High Quality Ethylene Glycol Antifreeze Containing Anti-corrosion for Aluminum Engine Inhibitors Coolant and Water

Mixed Ratio: 50%/50%
Total amount: 2.4 L (2.11 Imp qt, 2.54 US qt)
Reservoir Tank Capacity: 0.49 L (0.43 Imp qt, 0.52 US qt)
From "LOW" to "FULL" Level: 0.14 L (0.12 Imp. qt, 0.15USqt)

WARNING:
Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be blown out under pressure, which could cause serious injury.
When the engine has cooled, open the radiator can by the following procedure: Place a thick rag, like a towel, over the radiator cap, slowly rotate the cap counterclockwise to the detent. This procedure allows any residual pressure to escape. When the hissing sound has stopped, press down on the cap while turning counterclockwise and remove it.

(1) "FULL" level  (2) "LOW" level

Coolant Level Check 

1. Check:

•Coolant level Coolant level low > Add sufficient coolant.

2.  Remove:

• Reservoir tank cap (3)

• Cap retainer (4)

• Radiator cap (5)

3.  Add:

• Coolant

CLUTCH ADJUSTMENT

1.  Loosen the adjuster locknut (1)

2.  Adjust the clutch lever free play (a) by turning adjuster (2) in or out.

Free Play (a): 2 - 3mm (0.08-0.12 in)

3.  If free play can not be adjusted, adjust by clutch cable length adjuster.

4.  Loosen the adjuster locknuts (1)

5.  Adjust clutch lever free play (a) by turning clutch cable length adjuster (2)

IGNITION TIMING CHECK

Flywheel is marked as follows:

(1) Pickup coil mark

(2) TDC for No. 1 cylinder

(3) Firing range for the No. 1 cylinder

1. Check:

• Ignition timing

Ignition timing check steps:

•  Remove the cover.

•  Connect the Timing Light (YU-08037) (1) to No. 1 cylinder spark plug lead.

•  Warm up the engine and let it idle at the specified idle speed of 1.050 ± 50 r/min.

•  Visually check the upper pickup coil mark (T) is within the firing range (2) indicated on timing plate.

Incorrect firing — Check timing plate and/or pickup assembly (tightness damage)

Refer to CHARTER 6. "ELECTRICAL" for further information.

(1) Pickup coil mark.

(2) Firing range for the No. 1 cylinder

NOTE:
Insufficient compression pressure will result in performance loss.

1.  Measure:
•Valve clearance

Out of specification > Adjust.

2.  Warm up the engine.

3.  Remove:
•Spark plugs

4.  Measure:

• Compression pressure

Compression pressure measurement steps:

• Install the Compression Gauge (90890-03081) (1) using an adapter.

• Crank over the engine with the electric starter (be sure the battery is fully charged) with the throttle wide-open until the compression reading on the gauge stabilizes.

• Check readings with specified levels (See chart).

Compression Pressure (at sea level):

Standard: 1,059 kPa (10.8 kg/cm², 154 psi)

Minimum: 1,098 kPa (11.2 kg/cm², 159 psi)

Maximum: 1,138 kPa (11.6 kg/cm², 165 psi)

WARNING:
When cranking the engine, ground all of the spark plug leads to prevent sparking.

• Repeat the previous steps for the other cylinders.

• If pressure falls below the minimum level:

1)  Squirt a few drops of oil into the affected cylinder.

2)   Measure the compression again.

Compression Pressure (with oil introduced into cylinder)

NOTE:
The different between the highest and lowest cylinder compression readings must not vary more than the specified value.
Difference between Each Cylinder: Less than 98 kPa (1 kg/cm², 14 psi)

(1) Oil

FINAL GEAR OIL Oil Level Measurement

1.  Place the motorcycle on a level area and place on its centerstand.

2.  Remove the oil filler cap

3.  Observe the  oil level (2) and add oil if necessary.

NOTE:
Oil level must be up to the brim of the filler hole.

CAUTION:
Be sure that no foreign material enters the final gear case.

Gear Oil Replacement

1.  Place a receptacle under the final gear case.

WARNING:
Spilling oil on the tires  or on the ground under the tires will reduce traction and may result in an accident. Use a funnel, stiff piece of card, plastic or similar to ensure all oil is directed into the receptacle.

2.  Remove the filler cap and drain plug (1). Drain final gear oil into the receptacle.

3.  Re-install the drain plug. Torque to 23 Nm (2.3 m-kg, 17 ft-lb).

4. Fill the gear case to the specified level.

Final Gear Oil: SAE 80 API "GL-4" Hypoid gear oil

Oil Capacity: 0.20 L (0.18 Imp qt, 0.21 US qt)

NOTE:.
If desired, an SAE 80W90 Hypoid gear oil may be used for all conditions.

5. Install the filler cap. Torque cap to  23 Nm (2.3 m-kg, 17 ft-lb)

AIR FILTER

1. Remove the seat, fuel tank and rubber cover.

2. Remove the air filter cover (1)

3.  Eliminate dust using compressed air.

Note:
Blow out dust from the inside out.

4.  Inspect the element and replace if damaged. 

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

5. Install the element back in the airbox. Installation steps are the reverse of removal.

CAUTION:
Make sure the element cover fits into the corresponding filter case edge.

FRONT BRAKE

Brake Fluid Inspection

1. Check the Brake fluid level. Replenish as required.

NOTE:
Use only DOT 3 or equivalent fluid from a sealed container.

WARNING:
Be sure that:
•Water does not enter the master cylinder when refilling. 
•Spilled fluid is cleaned up immediately to prevent painted surfaces or plastic parts from eroding.

(1) Lower level

Front Brake Lever Free Play Adjustment

1.  Loosen the adjuster locknut (1)

2.  Adjust the free play (a) by turning the adjuster (2) until the free play (a) is within the specified limits.

Brake Lever Free Play (a): 2- 5 mm (0.08- 0.20 in)

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

3. Tighten the adjuster locknut

Brake Pad Inspection

1.  Activate the brake lever.

2.  Inspect the wear indicator (1). If the indicator almost contacts disc (2), replace pads. Refer to "CHASSIS."

REAR BRAKE

Rear Brake Pedal Height Adjustment

1.  Loosen the adjuster locknuts (1)

2.  Adjust the brake pedal height (a) by turning the adjuster (2) until the brake pedal position is at the specified height.

Brake Pedal Height (a): 10 mm (0.4 in) Below the Top of the Footrest

WARNING:
Adjust pedal height, then adjust brake pedal free play.

(1) Wear limit line

Rear Brake Shoe Inspection

1. Depress brake pedal.

2.  Inspect the wear indicator (2). if the indicator is at wear limit line (1), replace brake shoes.

Rear Brake Pedal Free Play Adjustment

1. Rotate the adjuster nut (1). Turn it clockwise or counterclockwise until proper brake pedal free play is attained.

Brake Pedal Free Play: 20-30 mm (0.8-1.2 in)

WARNING:
Check to verify correct brake light operation after adjustment.

Brake Light Switch Adjustment

1. Hold the switch body (1)  with your hand so that it does not rotate and turn the adjusting nut (2) .

Cable inspection and lubrication steps:

• Remove the two screws that secure throttle housing to handlebar.

• Hold cable end high and apply several drops of lubricant to cable.

• Coat metal surface of disassembled throttle twist grip with suitable all-purpose grease to minimize friction.

•Check for damage to cable insulation. Replace any corroded or obstructed cables.

• Lubricate any cables that do not operate smoothly.

Yamaha Chain and Cable Lube or SAE 10W30 Motor Oil

BRAKE AND SHIFT PEDALS/ BRAKE AND CLUTCH LEVERS

Lubricate pivoting parts of each lever and pedal.

Yamaha Chain and Cable Lube or SAE 10W30 Motor Oil

CENTERSTAND AND SIDESTAND

Lubricate centerstand and sidestand at their pivot points.

Yamaha Chain and Cable Lube or SAE 10W30 Motor Oil

FRONT FORK OIL CHANGE

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

1. Place a suitable stand under the engine to raise the front wheel off the ground.

2. Remove the air valve cap (1)

NOTE:
Keep the valve (2) open by pressing it for several seconds so that the air can be let out of the inner tube.

3.  Loosen the inner tube pinch bolt (1)

4.  Remove the cap bolt (2)

5. Remove the drain screw (1). Drain the fork oil.

WARNING:
Do not allow any oil to contact the disc brake components. If oil is discovered, be sure to remove it, otherwise diminished braking capacity and damage to the rubber components of the brake assembly will occur.

6. Inspect:

•O-ring (1) (Cap-bolt) 
•Gasket (Drain bolt screw) 

Replace if worn or damaged.

7.  Install the drain screw

8.  Fill the front forks.

Each Fork:

389 cm³ (13.7 Imp oz, 13.2 US oz)

After filling purnp the forks slowly up and down to distribute the oil. 

9. Tighten the cap-bolt and pinch bolt

Cap Bolt: 23 Nm (2.3m.kg, 17 ft-lb) 

Pinch Bolt: 20 Nm (2.0 m-kg, 14 ft-lb)

10.  Pressurize Fork with specified amount of air. Refer to "Front fork adjustment".

11.  Install the fork cap

Maximum Air Pressure: 118 kPa (1.2 kg/,cm 17.1 psi) Do not exceed this amount.

FRONT FORK ADJUSTMENT

1. Place motorcycle on centerstand, then elevate front wheel.

NOTE:
Be sure there is no weight on the front end of the motorcycle and the fork tube is at room temperature when air pressure is checked and adjusted.

2.  Remove the fork cap

3.  Measure the air pressure with an air gauge and adjust as needed.

NOTE:
Increased air pressure causes stiffer suspension; decreased pressure causes softer suspension.

CAUTION:
Do not use a high pressure air supply that will overpressurize the forks faster than the operator can control. Use only a manual pump or low pressure supply to avoid seal damage.

Standard Air Pressure: 39.2 kPa (0.4 kg/cm³, 5.7 psi)

Maximum Air Pressure: 118 kPa (1.2 kg/cm², 17.1 psi)

Minimum Air Pressure: Zero

4. Install the Fork cap 

REAR SHOCK ABSORBER ADJUSTMENT

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

Standard Position: A       A. - Softest E. - Stiffest

WARNING:
Always adjust each shock absorber to the same setting. Uneven adjustment can cause poor handling and loss of stability.

Steering Head Inspection

1.  Place the motorcycle on its centerstand, then elevate the front wheel.

2.  Check the steering assembly bearings. Grasp the bottom of the forks and gently rock the fork assembly back and forth. Adjust if any looseness can be detected.

Adjustment

Steering head adjustment steps:

• Loosen the pinch bolts (1) .

• Remove the handlebar securing bolts (2) .

• Remove the handlebar. 

•Remove the steering stem nut (3) .

 •Remove the steering crown (4) . 

•Remove the lock washer (5). 

•Loosen the upper ring nut (6) .

 •Tighten the lower ring nut (7)

Ring Nut (Lower): 50 Nm (5.0 m.kg, 36 ft-lb)

NOTE:
The tapered side of ring nuts must face downward.

• Loosen the ring nut (7) completely and retighten it to specification.

Rint Nut (Lower): 6Nm (0.6 m-kg, 4.3 ft-lb)

• Check the steering stem by turning it lock to lock. If there is any binding, remove the steering bearings (8) .

(See CHAPTER 6, STEERING HEAD for more details.)

• Hand-tighten the upper ring nut (6) , then align the slots of both ring nuts. If not aligned, hold the lower ring nut (7) and tighten the other until they are aligned.

• Install the lock washer (5).

NOTE:
Make sure the lock washer tab is placed in the slots.

• Install the steering crown (4) and tighten the steering stem nut (3) to specification.

Steering Stem Nut: 110 Nm (11.0 m-kg, 80 ft-lb)

• Install the handlebar (3) and torque the bolt (2) to specification.

Pinch Bolt: 20 Nm (2.0m.kg, 14 ft-lb)

Handlebar Bolt: 20 Nm (2.0 m-kg, 14 ft-lb)

• Install the fork and bolt caps.

Front Wheel Bearings

1. Raise the front end of the motorcycle, and spin the wheel by hand. Touch the axle or front fork white spinning the wheel. Replace the bearings if any vibration is detected.

Note: It may be necessary to retract the brake pads from the disk in order to freely rotate the wheel.

Rear Wheel Bearings

1.  Remove the rear wheel

2.  Check the bearing movement by rotating it with the fingers. Replace if any roughness or wear is detected.

TUBELESS TIRES AND ALUMINUM WHEELS

WARNING:
 Always inspect aluminum wheels before a ride.
Do not attempt any repairs to the wheel; replace any defective wheel.
Do not attempt to use tubeless tires on a wheel designed for use with tube-type tire only. Tire failure and subsequent personal injury may result from sudden deflation.

• Be sure to install the proper tube when using tube-type tires.

• New tires have a relatively poor adhesion on the road surface so do not allow them to be subjected to high speed load from maximum speed until after a break-in run of approx. 100 km (60 mi).

• Always use the correct tire inflation pressure according to the operating conditions.

(C)   Tubeless tire

(D)   Tube type tire

(1)   Air valve

(2)    Aluminum wheel {Tubeless type)

(3)   Tube

(4)   Aluminum wheel (Tube type)

Always perform the following steps to ensure safe operation, maximum tire performance and long service. 

1. Measure the tire pressure and adjust as necessary. 

* Load is the total weight of cargo, rider, passenger, and accessories.

2. Inspect the tire surfaces for wear or damage. Replace as required.

Minimum Tire Tread Depth: (Front and Rear) 1.0 mm (0.04 in)

(1) Tread depth

(2)  Side wall

(3)  Wear indicator

3. Inspect the aluminium wheels for damage or cracks. Never attempt even small repairs to the wheel.

NOTE:
Always balance the wheel when a tire or wheel has been changed or replaced.

WARNING:
Ride conservatively after installing a tire to allow it to seat itself properly on the rim.

1.  Disconnect:

• Negative lead (1)

• Positive lead (2)

• Breather hose (§)

2.  Remove the battery

3. Check the fluid level. It should be between upper (1) and lower (2) level marks.

CAUTION:
Refill with distilled water only; tap water contains minerals harmful to a battery.

4.  Inspect the breather hose (1) for obstructions. Clear or replace as necessary.

5.  Connect the breather hose (1). Be sure the hose is properly attached and routed.

HOW TO ROUTE BATTERY BREATHER HOSE.

CAUTION;
Always charge a new battery before using it to ensure maximum performance.

Charging Current: 1.4 amps/10 hrs

Specific Gravity:

1.280 at 20°C(68°F)

WARNING: Battery electrolyte is dangerous; it contains sulfuric acid and therefore is poisonous and highly caustic. Always follow these preventive measures:
• Avoid bodily contact with electrolyte as it can cause severe burns or permanent eye injury.
• Wear protective eye gear when handling or working near batteries.

HEADLIGHT

Headlight Bulb Replacement

1.  Remove securing screws (1) from light unit assembly/headlight body.

2.  Disconnect the headlight lens unit leads

3. Remove the light unit assembly

4.  Rotate the bulb holder (1) counterclockwise.

5.  Remove the defective bulb

6. Install new bulb and secure with bulb holder.

CAUTION:
• Avoid touching glass part of bulb.
• Keep the bulb free from oil otherwise, transparency of glass, bulb life, and luminous flux will be adversely affected.
• If oil gets on bulb, clean it with a cloth moistened thoroughly with alcohol or lacquer thinner.

WARNING:
Do not touch the headlight bulb when it is on, as the bulb generates enormous heat; keep flammable objects away.

7. Install the light unit assembly to headlight body.

Headlight Beam Adjustment Horizontal adjustment: 

1. Rotate the horizontal adjusting screw (1)

Vertical adjustment: 1. Rotate:

• Vertical adjusting screw (2)

FUSE

The fuse box is under the indicator light panel. The main fuse is under the seat.

(1) Main fuse

(2) Spare fuses

(3) Other fuse block

Blown fuse procedure steps:

• Turn off ignition and the circuit.

• Install a new fuse of proper amperage.

• Turn on switches to verify operation of electrical device.

• If fuse blows immediately again, check circuit in question.

WARNING:
Do not use fuses of higher amperage rating than recommended. Extensive electrical system damage and fire could result from substitution of a fuse of improper amperage.

RADIATOR PIPES, CARBURETOR JOINT, AND OIL DELIVERY PIPE

1.  Remove:
• Radiator pipe 1
• Cover (Right) 2

2.  Drain the coolant (in the cylinder) by removing drain bolts 3  

3. Remove;
• Water pump joint 1
• Radiator pipes 2
• Carburetor joints
• Bypass hose 3

4.  Remove:
• Oil delivery pipe union bolts 1
• Copper washers
• Cylinder head side covers 2

5.  Loosen the cam chain tensioner end plug 3

6.  Remove the cam chain tensioner assembly 4

CYLINDER HEAD AND CYLINDER

1. Remove the cylinder head cover

NOTE:
Piston and cylinder can be removed, when necessary, without removing the camshaft.

The main steps are as follows.
 • Disconnect the cam chain using Cam Chain Cutter 1 (90890-01112).

• Remove the cylinder head nuts in the camshaft case using Hexagon Wrench 2 .
• Remove the cam shaft, cam shaft case and cylinder head as assembly.

2. Remove:
• Cam chain guide (Upper) 1
• Camshaft cap (I3) 2
• Camshaft cap (E3) 3
• Dowel pins

3.  Remove:
• Cam chain sprocket bolts 1 Use 2 2 mm (0.88 in) wrench to hold camshaft.
• Camshaft caps (I1, I2, I4, E1,E2, E4)
• Dowel pins
• Camshafts
• Cam chain guide (Front) 1

4.  Remove:
• Cylinder head nut
• Cylinder head

NOTE:
Follow the numerical order shown in photo, start by loosening each nut 1 /4 turn until all are loose.

5. Remove:
• Cylinder head gasket 1
• Dowel pins 2
• Cylinder
• Oil delivery pipes 3
• Cylinder base gasket
• Dowel pins

PISTON AND CAM CHAIN GUIDE

Mark each piston so it can be reinstalled in the appropriate cylinder. 
1. Remove: 
• Piston pin clips 1
• Piston pins 2

NOTE:  Before removing the piston pin clip, cover the crankcase with a clean rag so you will not accidentally drop the clip into the crankcase.

• Pistons
• Cam chain guide (Rear) 3

STARTER MOTOR AND GENERATOR

1. Remove: 
• Starter motor bolts 
• Starter motor assembly 1
• Generator cover 2

2. Remove:
• Stator coil 1
• Gasket 2

3.  Attach the rotor Holding Tool (90890-04043) 1

4.  Remove the rotor holding bolt 2

5.  Attach:
• Rotor Puller Adapter (90890-04052) 1
• Rotor Puller (90890-01080) 2

6.  Remove the rotor 3

PICKUP COIL

1. Disconnect:
• Oil level switch lead 1
• Neutral switch lead 2
• Pickup coil lead (from clamps 3 )

2. Remove:
• Timing plate 1
• Dowel pin 2
• Pickup coil assembly 3

SHIFTER AND MIDDLE GEAR

1. Remove:
• Crankcase cover (Left) 1
• Gasket
• Dowel pin 2
• Shift shaft 3
• Shift lever 4
• Oil level maintaining plug 5

2. Remove:

• Middle driven gear housing 1
• Shims 2

3. Remove:

• Bearing retainer 1 Use Torx Driver #40 (90890-04049).

CRANKCASE

1. Remove:
• Bolts (Crankcase) 
• Clamps
• Battery negative lead

NOTE:
• Remove the bolts starting with the highest numbered one.
• The embossed numbers in the crankcase designate the crankcase tightening sequence.

Upper crankcase

Lower crankcase

2. Remove:
• Lower crankcase
• Blind plug (from crankcase right end)
• Crankshaft bearings

NOTE:
Identify each crankshaft bearing position very carefully so that it can be reinstalled in its original place.

MAIN AXLE AND MIDDLE DRIVE GEAR

1. Remove:
• Middle drive gear 1
• Main axle 2
• Bearing 3
• Dowel pins 4
• O-ring 5

A.C.G. SHAFT, STARTER DRIVE, AND CRANKSHAFT

1. Remove housing using Torx Driver #30 (90890-05245)

2. Remove:
• Oil spray nozzle 1
• A.C.G. shaft 2

Use Armature Shock Puller (90890-01290) and (90890-01291)3

3. Remove:
• Starter clutch assembly 1
• Crankshaft

5.  Bend the lock washer tab 1

6.  Remove:
• Starter idle gear shaft bolt 2
• Lock washer
• Stopper plate 
• Starter idle gear shaft 3
• Starter idle gear 4

SHIFT CAM AND DRIVE AXLE

1. Remove: 
• Guide bar 1  
• Shift forks 2

2. Remove:
• Neutral switch 1 
• Bolts 2  
• Stopper plate 3
• Shift cam locating pin 4
• Shift cam 5

3. Remove:
• Drive axle bearing cover 1
• 5th wheel gear 2

4. Remove the drive axle assembly

1. Remove
• Lifters 1
• Valve pads 2

NOTE:
Identify each lifter and pad position very carefully so that it can be reinstalled in its original place.

2. Measure the warpage using a precision straight edge or surface plate and feeler gauges. Resurface if warpage exceeds allowable limit.

Cylinder Head Warpage: Less than 0.03 mm (0.0012 in)

3. Remove the camshaft case 1

4. Remove:
• Camshaft case gasket 1
• Dowels 2  
• Cylinder head nuts
• Plain washers

5. Attach:
• Valve Spring Compressor (90890-04019) 1
• Attachment (90890-04108) 2

6. Remove:
• Valve retainers 1
• Valve spring seat 2
• Valve spring 3
• Oil seal 4
• Valve spring seat 5
• Valve 6

NOTE:
Deburr any deformed valve stem end. Use an oil stone to smooth the stem end.

1 Deburr   2 Valve stem

7. Eliminate: 
• Carbon deposit (from combustion chamber) Use rounded scraper.

NOTE:
Do not use a sharp instrument and avoid damaging or scratching:
• Spark plug threads
• Valve seat
• Aluminum

8. Install:
• Valves

NOTE:
Be sure the "1AA : " mark 1 valves are for intake left and right and "1AA •" mark 2 for intake center.

9. Install the valve springs

NOTE:
• All valve springs must be installed with the larger pitch 1 upward as shown.
• Be sure the "Blue" spring is for intake and "Red" for exhaust.

2  Smaller pitch

10. Install:
• Dowels 1
• Camshaft case gasket 2

NOTE:
Be sure the "UP" mark face to upward.

• Plain washers 3
• Cylinder head nuts 4

11. Install the camshaft case 1. Torque the camshaft case bolts to 10 Nm (1.0m-kg, 7.2ft-ft)

1. Measure the valve stem clearance

Use a bore gauge 3 to determine the valve guide inside diameter.

Valve Guide Inside Diameter Limit: 5.05 mm (0.199 in)

2. Measure the valve stem diameter with a micrometer. Replace guide if clearance exceeds specification.

Valve stem clearance = Valve guide inside diameter 1 minus  Valve stem diameter 2

Valve Stem Clearance Limit:

Intake 0.08 mm (0.003 in)
Exhaust 0,10 mm (0.004 in)

3. Examine the valve face for pitting or wear and regrind as necessary. Measure the valve face as indicated below and replace if valve cannot be brought back to specification.

Minimum Thickness (Service limit) 1 : 0.7 mm (0.028 in) 

Beveled 2 : 0.35 mm (0.014 in) 

Minimum Length (Service limit) 3 :14.5 mm (0.6 in)

4. Check:
• Valve stem end Mushroom shape and/or diameter. Replace if larger than rest or stem. 
• Runout. Replace if it exceeds specification.

Maximum Valve Stem Runout: 0.01 mm (0.0004 in)

5. Inspect the valve guide for signs of wear and/or oil leakage. Replace if excessive.

NOTE:
Heat the
cylinder head in an oven to 100°C (212°F) to ease valve guide removal
and reinstallation and to maintain correct interference fit.

Valve Guide Replacement 

1. Remove the valve guide. Use Valve Guide remover 1 (90890-04097)

NOTE
• Always replace valve guide if valve is replaced.
• Always replace oil seal if valve is removed.

2. Install the new valve guide with Valve Guide Installer 1 (90890-04098) and Valve Guide Remover (90890-04097).

3. Bore valve guide 1 to obtain proper valve stem clearance. Use 5 .0 mm (0.20 in) Reamer 2 (YM-04099).

Valve Seat

1. Inspect the valve seat for pitting/wear. Cut new faces as required.

2. Measure the valve seat width 1. Follow the next steps if out of specification.

3.  Apply:
• Mechanic's bluing dye (Dykem) (to valve and seat)
• Fine grinding compound (Small amount) (to valve face surface)

4.  Position the valve into the cylinder head.

CAUTION:
Do not allow any compound to contact the valve stem or guide. Flush thoroughly as required.

5.  Spin it rapidly back and forth, then lift valve and clean off all grinding compound.

6.  Inspect the valve seat surface. Wherever valve seat and valve face made contact, blueing will have been removed.