Yamaha tmax XP500A, Service Manual

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5 - 26
ENG
VALVES AND VALVE SPRINGS
e. Apply a fine lapping compound to the valve
face and repeat the above steps.
f. After every lapping procedure, be sure to
clean off all of the lapping compound from
the valve face and valve seat.
g. Apply Mechanic’s blueing dye (Dykem) onto
the valve face.
h. Install the valve into the cylinder head.
i. Press the valve through the valve guide and
onto the valve seat to make a clear impres-
sion.
j. Measure the valve seat width
b
again. If
the valve seat width is out of specification,
reface and lap the valve seat.
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EAS00241
CHECKING THE VALVE SPRINGS
The following procedure applies to all of the
valve springs.
1. Measure:
• valve spring free length
a
Out of specification
→
Replace the valve
spring.
2. Measure:
• compressed spring force
a
Out of specification
→
Replace the valve
spring.
b
Installed length
Valve spring free length (intake
and exhaust)
35.59 mm (1.40 in)
<Limit>: 33.81 mm (1.33 in)
Compressed spring force
Intake valve spring
91.2 ~ 104.9 N at 30.4 mm
(9.3 ~ 10.7 kg at 30.4 mm,
20.5 ~ 23.6 lb at 1.20 in)
Exhaust valve spring
91.2 ~ 104.9 N at 30.4 mm
(9.3 ~ 10.7 kg at 30.4 mm,
20.5 ~ 23.6 lb at 1.20 in)