650G (Euro)

Cleaning the Hitachi Carb

This series assumes you took the carbs apart, and are trying to figure out how to put them back together again. If you haven’t taken them apart yet, it’s a good idea to skim through this first anyway. Address any questions to: xj-owners@micapeak.com, and we’ll try to talk you through it.

 

Pictures and text by Dwayne Verhey

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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

Cylinder Head Removal

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 prevent any harmful foreign material from getting into the engine oil.

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.

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

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.

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

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

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.

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

Middle Gear -- Inspection and Repair

P. Middle Gear

1. Damper disassembly

NOTE:
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.