kymco mo x500 Instruction De Maintenance
8. CYLINDER HEAD/VALVES
8-2
XCITING 500
SERVICE INFORMATION
GENERAL INSTRUCTIONS
• The cylinder head can be serviced with the engine installed in the frame. Coolant in the radiator
• 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
• After removal, mark and arrange the removed parts in order. When assembling, install them in
the reverse order of removal.
SPECIFICATIONS
Unit: mm (in)
Item
Standard
Service Limit
IN
0.1 mm (0.004 in)
⎯
EX
0.1 mm (0.004 in)
⎯
Cylinder head compression pressure 13 kg/cm
2
(185 psi, 1300 kPa)
⎯
Cylinder head warpage
⎯
0.05 (0.002)
IN
37.2614 (1.4905)
37.11 (1.4844)
EX
37.0084 (1.4803)
36.86 (1.4744)
IN
10 (0.4)～10.015 (0.4006)
10.1 (0.404)
EX
10 (0.4)～10.015 (0.4006)
10.1 (0.404)
Valve rocker arm shaft
IN
9.975 (0.399)～9.99 (0.3996)
9.9 (0.396)
O.D.
EX
9.975 (0.399)～9.99 (0.3996)
9.9 (0.396)
IN
4.975 (0.199)～4.99 (0.1996)
4.925 (0.197)
EX
4.955 (0.1982)～4.97 (0.1988)
4.915 (0.1966)
IN
5 (0.2)～5.015 (0.2006)
5.03 (0.2012)
EX
5 (0.2)～5.015 (0.2006)
5.03 (0.2012)
Valve stem-to-guide
IN
0.01 (0.004)～0.037 (0.0015)
0.08 (0.0032)
clearance
EX
0.03 (0.0012)～0.057 (0.0023)
0.1 (0.004)
TORQUE VALUES
Cylinder head bolt (13)
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
Valve spring compressor
E040
Valve clearance (cold)
Camshaft cam height
Valve rocker arm I.D.
Valve guide I.D.
Valve stem O.D.