Yamaha YFM700RV 2009, Руководство по обслуживанию, Страница: 178 / 409

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ENG
VALVES AND VALVE SPRINGS
5. Measure:
• valve stem runout
Out of specification
→
Replace.
NOTE:
_
• When installing a new valve, always replace
the valve guide.
• If the valve is removed or replaced, always
replace the valve stem seal.
6. Eliminate:
• carbon deposits
(from the valve face and valve seat)
7. Check:
• valve seat
Pitting/wear
→
Replace the valve seat.
Valve stem runout
0.010 mm (0.0004 in)
8. Measure:
• valve seat width
a
Out of specification
→
Replace the valve
seat.
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a. Apply Mechanic’s blueing dye (Dykem)
b
to
the valve face.
b. Install the valve into the cylinder head.
c. Press the valve through the valve guide and
onto the valve seat to make a clear pattern.
d. Measure the valve seat width. Where the
valve seat and valve face made contact,
blueing will have been removed.
e. If the valve seat is too wide, too narrow, or
the seat is not centered, the valve seat must
be refaced.
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Valve seat width
Intake
1.00 ~ 1.20 mm
(0.0394 ~ 0.0472 in)
<Limit>: 1.60 mm (0.0630 in)
Exhaust
1.00 ~ 1.20 mm
(0.0394 ~ 0.0472 in)
<Limit>: 1.60 mm (0.0630 in)