Yamaha Tracer MT09TRAH 2017 User Manual

VALVES AND VALVE SPRINGS
5-26
TIP
After replacing the cylinder head or replacing the
valve and valve guide, the valve seat and valve
face should be lapped.
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a. Apply a coarse lapping compound “a” to the
valve face.
NOTICE
ECA13790
Do not let the lapping compound enter the
gap between the valve stem and the valve
guide.
b. Apply molybdenum disulfide oil onto the
valve stem.
c. Install the valve into the cylinder head.
d. Turn the valve until the valve face and valve
seat are evenly polished, then clean off all of
the lapping compound.
TIP
For the best lapping results, lightly tap the valve
seat while rotating the valve back and forth be-
tween your hands.
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 blue layout fluid “b” 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 contact width “c”
again. If the valve seat contact width is out of
specification, reface and lap the valve seat.
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EAS30286
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.
Free length (intake)
39.31 mm (1.55 in)
Limit
37.34 mm (1.47 in)
Free length (exhaust)
37.78 mm (1.49 in)
Limit
35.89 mm (1.41 in)

Yamaha Tracer MT09TRAH 2017 Specifications

General

Brand	Yamaha
Model	Tracer MT09TRAH 2017
Category	Motorcycle
Language	English