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.
Intake/Exhaust valve
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.
Crankcase disassembly
1. Remove the right-front crankcase cover.
2. Remove the upper crankcase bolts, starting the highest numbered bolt.
Turn over the engine and remove the lower crankcase bolts.
CRANKCASE TIGHTENING SEQUENCE
LOWERCASE
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.
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.
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
1. Remove the cylinder head cover.
2. Remove the left crankcase cover (pickup coil cover).
3. Remove the cam chain tensioner.
Use a 19 mm wrench on the timing plate flats to rotate the crankshaft counterclockwise until the engine is at T.D.C.
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