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 Top Dead Centre.
CAUTION: 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.
CAUTION: 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 cham guide
8. Remove the cam caps. Note the location ofthe cam caps as shown. 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 camshafts and sprockets from under the chain and remove the camshafts 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.
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. Hoiding bolt 2 Rear cam chain guide
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 lifter 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.
NOTE: 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.
DEBURR VALVE STEM
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
1. Make each piston to aid in reassembly.
2. Place a clean towel or rag into the cranckcase to keep circlips and material from falling into the engine.
3. Remove piston pin clips, piston pins, and pistons.
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