Yamaha Wolverine YX70EPNG, Service Manual

Page: 109 / 503

PERIODIC MAINTENANCE
3-4
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6. Remove:
• Camshafts
Refer to “CAMSHAFTS” on page 5-10.
7. Adjust:
• Valve clearance
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a. Remove the valve lifter “1” and the valve pad
“2” with a valve lapper “3”.
TIP
• Cover the timing chain opening with a rag to
prevent the valve pad from falling into the
crankcase.
• Make a note of the position of each valve lifter
“1” and valve pad “2” so that they can be in-
stalled in the correct place.
b. Calculate the difference between the speci-
fied valve clearance and the measured valve
clearance.
Example:
Specified valve clearance = 0.10–0.20 mm
(0.0039–0.0079 in)
Measured valve clearance = 0.27 mm
(0.0106 in)
0.27 mm (0.0106 in)–0.20 mm (0.0079 in) =
0.07 mm (0.0028 in)
c. Check the thickness of the current valve pad,
and then calculate the sum of the values ob-
tained to determine the required valve pad
thickness and the valve pad number.
TIP
• The number “a” marked on the valve pad indi-
cate the valve pad thickness.
• Refer to the following table for the available
valve pads.
• If there are no available valve pads with the
same thickness as the calculated valve pad
thickness, select the next thickest valve pad.
Thickness gauge
90890-03180
Feeler gauge set
YU-26900-9
Valve lapper
90890-04101
Valve lapping tool
YM-A8998
1
Number “a” Thickness
145 1.450 mm (0.05709 in)
150 1.500 mm (0.05906 in)
155 1.550 mm (0.06102 in)
160 1.600 mm (0.06299 in)
162 1.625 mm (0.06398 in)
165 1.650 mm (0.06496 in)
167 1.675 mm (0.06594 in)
2
1
177
a