Yamaha GRIZZLY Ultramatic YFM660FP, Service Manual

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ENG
VALVES AND VALVE SPRINGS
3.Check:
●
Valve face
Pitting/wear
→
Grind the face.
●
Valve stem end
Mushroom shape or diameter larger than the
body of the stem
→
Replace.
4.Measure:
●
Margin thickness
a
Out of specification
→
Replace.
Margin thickness:
Intake:
0.85 ~ 1.15 mm
(0.0335 ~ 0.0452 in)
Exhaust:
0.85 ~ 1.15 mm
(0.0335 ~ 0.0452 in)
5.Measure:
●
Runout (valve stem)
Out of specification
→
Replace.
NOTE:
●
When installing a new valve always replace
the guide.
●
If the valve is removed or replaced always
replace the oil seal.
6.Eliminate:
●
Carbon deposits
(from the valve face and valve seat)
7.Check:
●
Valve seats
Pitting/wear
→
Reface the valve seat.
Runout limit:
0.01 mm (0.0004 in)