Troubleshooting - KYMCO MXU 500 Owner's Manual

8. CYLINDER HEAD/VALVES
TORQUE VALUES
Cylinder head bolt (1 – 4)
Cylinder head bolt (5 – 13)
Cylinder head nut
Cylinder head cover bolt
Breather separator bolt
Cam chain tensioner bolt
Tensioner sealing bolt
Rocker arm shaft
Cam chain guide pivot bolt
Water joint bolt
SPECIAL TOOLS
Valve spring compressor

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
Compression too low
Compression too low
Incorrect valve clearance adjustment
Burned or bend valves
Incorrect valve timing
Broken valve spring
Poor valve and seat contact
Leaking cylinder head gasket
Warped or cracked cylinder head
Poorly installed spark plug
Compression too high
Excessive carbon build-up in combustion
chamber
8-3
4.8 kgf-m (48 N-m, 35 lbf-ft)
2.3 kgf-m (23 N-m, 17 lbf-ft)
1 kgf-m (10 N-m, 7 lbf-ft)
1 kgf-m (10 N-m, 7.2 lbf-ft)
1.3 kgf-m (13 N-m, 9 lbf-ft)
1.2 kgf-m (12 N-m, 8.6 lbf-ft)
1 kgf-m (10 N-m, 7 lbf-ft)
4.5 kgf-m (45 N-m, 32 lbf-ft)
2 kgf-m (20 N-m, 15 lbf-ft)
1.2 kgf-m (12 N-m, 8.6 lbf-ft)
A120E00040
White smoke from exhaust muffler
Abnormal noise
Apply engine oil to threads
Apply engine oil to threads
Worn valve stem or valve guide
Damaged valve stem oil seal
Incorrect valve clearance adjustment
Sticking valve or broken valve spring
Damaged or worn camshaft
Worn cam chain tensioner
Worn camshaft and rocker arm
MXU 500