kymco mo bw250 Instruction De Maintenance

• The poor cylinder head operation can be diagnosed by a compression test or by tracing engine

top-end noises.

• Compression too low

• Worn valve stem or valve guide
• Damaged valve stem oil seal

Compression too low
• Incorrect valve clearance adjustment

• 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