KYMCO Mongoose/KXR 250 User Manual

7. CYLINDER HEAD/VALVES
7-3
Mongoose/KXR 250
TORQUE VALUES
Cylinder head cover bolt 0.8～1.2kgf-m
Cam shaft hold nut 2.3～2.7kgf-m Apply engine oil to threads
Tappet adjusting nut 0.7～1.1kgf-m
SPECIAL TOOLS
Valve spring compressor E040
Tappet adjuster E012
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 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 guide
• 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

KYMCO Mongoose/KXR 250 Specifications

General

Brand	KYMCO
Model	Mongoose/KXR 250
Category	Offroad Vehicle
Language	English