Yamaha 2007 XP500 Service Manual page 108

In order to be sure that the piston is at TDC, the
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alignment mark "c" on the intake camshaft
sprocket and the alignment mark "d" on the ex-
haust camshaft sprocket must align with the
cylinder head mating surface as shown in the
illustration.
d
c. Measure the valve clearance with a thickness
gauge "1".
1
NOTE:
If the valve clearance is incorrect, record the
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measured reading.
Measure the valve clearance in the following
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sequence.
Valve clearance measuring sequence
Cylinder #1 → #2 → #4 → #3
d. Turn the crankshaft 360° counterclockwise
and check the valve clearance of piston #2.
Cylinder #2
Cylinder #4
Cylinder #3
LLLLLLLLLLLLLLLLLLLLLL
8. Remove:
Intake camshaft
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c
180°
360°
540°
3-4
Exhaust camshaft
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ECA15B1015
CAUTION:
Before removing the camshafts from the cyl-
inder head, tilt up the engine at least 25°.
NOTE:
Refer to "CAMSHAFTS" on page 5-6.
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When removing the timing chain and cam-
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shafts, fasten the timing chain with a wire to re-
trieve it if it falls into the crankcase.
9. Adjust:
Valve clearance
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MMMMMMMMMMMMMMMMMMMMMM
a. Remove the valve lifter "1" and the valve pad
"2" with a valve lapper "3".
2
1
Valve lapper
90890-04101
Valve lapping tool
YM-A8998
NOTE:
Cover the timing chain opening with a rag to
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prevent the valve pad from falling into the
crankcase.
Make a note of the position of each valve lifter
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"1" and valve pad "2" so that they can be in-
stalled in the correct place.
2
b. Select the proper valve pad from the follow-
ing table.
Valve pad range
ENGINE
1
Nos. 120–240