KYMCO VITALITY 50 Manual page 94

6. 4-STROKE: CYLINDER HEAD/VALVES
TORQUE VALUES
Cylinder head cover bolt
Cam shaft hold nut
Tappet adjusting nut
SPECIAL TOOLS
Valve spring compressor
Tappet adjuster
TROUBLESHOOTING
x The poor cylinder head operation can be diagnosed by a compression test or by tracing engine
top-end noises.
Poor performance at idle speed
x Compression too low
Compression too low
x Incorrect valve clearance adjustment
x Burned or bend valves
x Incorrect valve timing
x Broken valve spring
x Poor valve and seat contact
x Leaking cylinder head gasket
x Warped or cracked cylinder head
x Poorly installed spark plug
Compression too high
x Excessive carbon build-up in combustion
chamber
6-3
0.8 1.2kgf-m
1.2 1.6kgf-m
0.7 1.1kgf-m
E040
E036
White smoke from exhaust muffler
x Worn valve stem or valve guide
x Damaged valve stem seal
Abnormal noise
x Incorrect valve clearance adjustment
x Sticking valve or broken valve spring
x Damaged or worn camshaft
x Worn cam chain guide
x Worn camshaft and rocker arm
VITALITY 50
Apply engine oil to threads