kymco mo kxr 50 Instruction De Maintenance
7
. CYLINDER HEAD/VALVES
(Mongoose/KXR 90)
7-2
Mongoose/KXR 90/50
SERVICE INFORMATION
GENERAL INSTRUCTIONS
• The cylinder head can be serviced with the engine installed in the frame.
• When assembling, apply molybdenum disulfide grease or engine oil to the valve guide movable
• When assembling, apply molybdenum disulfide grease or engine oil to the valve guide movable
parts, valve arm and camshaft sliding surfaces for initial lubrication.
• The camshaft is 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
• After removal, mark and arrange the removed parts in order. When assembling, install them in the
reverse order of removal.
SPECIFICATIONS
Item
Standard (mm)
Service Limit (mm)
IN
0.1
æ
EX
0.1
æ
Cylinder head compression pressure
16±2kg/cm_
Cylinder head warpage
æ
0.05
IN
26.4881
26.33
EX
25.8073
25.65
Valve rocker arm to shaft clearance
EX
0.034_ 0.09
0.1
Valve stem-to-guide
IN
0.010_ 0.037
0.06
clearance
EX
0.025_ 0.052
0.08
IN
32.3
30.8
Valve spring free length
EX
35
33.5
IN
3.47_ 3.87kg(at 26.0mm)
æ
Valve spring
compressed force
EX
8.29_ 10.19kg(at 29.0mm)
æ
Valve clearance (cold)
Camshaft cam height