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ENG
INSPECTION AND REPAIR
INSPECTION AND REPAIR
CYLINDER HEAD
1.Eliminate:
● Carbon deposit
Use a rounded scraper 1.
NOTE:
Do not use a sharp instrument to avoid
damaging or scratching:
● Spark plug threads
● Valve seat
● Cylinder head
2.Measure:
● Cylinder head warpage
Out of specification → Resurface/Replace.
Cylinder head warp:
Less than 0.10 mm (0.004 in)
INTAKE AND EXHAUST VALVE
1.Check:
● Valve face
● Stem end
Wear/Pitting/Out of specification →
Replace.
Minimum thickness (service limit)
a:
0.8 mm (0.031 in)
Beveled b:
0.5 mm (0.020 in)
Minimum length (service limit)
c:
4.0 mm (0.157 in)
2.Inspect:
● Valve stem end 1
Mushroom shape/Larger diameter than
rest of stem → Replace valve, valve guide,
and oil seal.
NOTE:
Deburr any deformed valve stem end 1.
Use an oil stone to smooth the stem end.
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