KYMCO KXR 250, Руководство по обслуживанию

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7
. CYLINDER HEAD/VALVES
7-2
Mongoose/KXR 250
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
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 reverse order of removal.
SPECIFICATIONS
Item Standard (mm) Service Limit (mm)
IN 0.1
⎯
EX 0.1
⎯
Cylinder head compression pressure 15
±
2kg/cm
²
Cylinder head warpage
⎯
0.05
IN 34.287 34.15
EX 34.1721 34.05
Valve rocker arm to shaft clearance
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 30.9 29.4
Valve spring free length
EX 41 39
IN 10.20
～
11.84kg(at 18.05mm)
⎯
Valve spring
compressed force
EX 19.14
～
22.02kg(at 21.5mm)
⎯
IN 0.8
⎯
Valve spring tilt
EX 1.07
⎯
Valve clearance (cold)
Camshaft cam height