Kymco XCITING 500 - Service Manual > Schematic Drawing, Service Information

SCHEMATIC DRAWING

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• The cylinder head can be serviced with the engine installed in the frame. Coolant in the radiator and water jacket must be drained first.
• When assembling, apply molybdenum disulfide grease or engine oil to the valve guide movable parts and valve arm sliding surfaces for initial lubrication.
• The valve rocker arms are lubricated by engine oil through the cylinder head engine oil passages.

  Clean and unclog the oil passages before assembling the cylinder head.

• After disassembly, clean the removed parts and dry them with compressed air before inspection.
• After removal, mark and arrange the removed parts in order. When assembling, install them in the reverse order of removal.

SPECIFICATIONS

TORQUE VALUES

Cylinder head bolt (13) 13 N*m (1.3 kgf*m, 9 lbf*ft) Apply engine oil to threads
Cylinder head bolt (1 - 4) 48 N*m (4.8 kgf*m, 35 lbf*ft) Apply engine oil to threads
Cylinder head bolt (5 - 12) 23 N*m (2.3 kgf*m, 17 lbf*ft) Apply engine oil to threads
Cylinder head cover bolt 10 N*m (1 kgf*m, 7 lbf*ft)
Cylinder head cover bolt 10 N*m (1 kgf*m, 7 lbf*ft)
Breather separator bolt 13 N*m (1.3 kgf*m, 9 lbf*ft)
Cam chain tensioner bolt 12 N*m (1.2 kgf*m, 9 lbf*ft)
Tensioner pivot bolt 10 N*m (1 kgf*m, 7 lbf*ft)
Rocker arm shaft 45 N*m (4.5 kgf*m, 32 lbf*ft)

SPECIAL TOOLS

Valve spring compressor E040

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

White smoke from exhaust muffler

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

Abnormal noise

• Incorrect valve clearance adjustment
• Sticking valve or broken valve spring
• Damaged or worn camshaft
• Worn cam chain tensioner
• Worn camshaft and rocker arm

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