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
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
ENGINE OVERHAUL
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.
ENGINE REMOVAL
NOTE:
It is not necessary to remove the engine in order to remove the following components:
• Piston
• Clutch
• Carburetor
• Oil pump
PREPARATION FOR REMOVAL
CHAPTER3. ENGINEOVERHAULING
At 5°C (40°F) or Higher:
SAE 20W40 Type SE Motor Oil
At 15°C (60°F) or Lower:
SAE 10W30 Type SE Motor Oil
VALVE CLEARANCE ADJUSTMENT
(1)Pad (2) Valve lifter (3) Valve retainer (4)Spring seat (5)inner spring (6) Outer spring (7) Spring seat (8) Oil seal (9) Valve
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A |
VALVE CLEARANCE (COLD): | |
Note: this fix does require mechanical ability and judgement. If you have never done anything like this before, you may decide to disassemble the transmission yourself (hey, everyone has to start somewhere) but I suggest you seek out the assistance of someone with some mechanical experience once you get inside. Just changing/repairing the gears may not be enough.
Problem: The transmission kicks and jumps out of second gear, under load. This rapidly gets worse and soon the bike won't take second gear at all.
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.
Cylinder head
MIDDLE GEAR/DAMPER
a. Middle gear lash 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.