kymco mo x500 Instruction De Maintenance

Page de 24
8. CYLINDER HEAD/VALVES
8-3
XCITING 500
TROUBLESHOOTING
• The poor cylinder head operation can be diagnosed by a compression test or by tracing engine
top-end noises.
Poor performance at idle speed
White smoke from exhaust muffler
• Compression too low
• Worn valve stem or valve guide
• Damaged valve stem oil seal
Compression too low
• Incorrect valve clearance adjustment
Abnormal noise
• Burned or bend valves
• Incorrect valve clearance adjustment
• Incorrect valve timing
• Sticking valve or broken valve spring
• Broken valve spring
• Damaged or worn camshaft
• Poor valve and seat contact
• Worn cam chain tensioner
• Leaking cylinder head gasket
• Worn camshaft and rocker arm
• Warped or cracked cylinder head
• Poorly installed spark plug
Compression too high
• Excessive carbon build-up in combustion
chamber