Yamaha XT660R, Service Manual

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5 - 19
ENG
2. Measure:
• camshaft lobe dimensions
a
and
b
Out of specification
→
Replace the cam-
shaft.
3. Measure:
• camshaft runout
Out of specification
→
Replace.
Camshaft lobe dimensions
Intake
a
43.488 ~ 43.588 mm
(1.7121 ~ 1.7161 in)
<Limit>:
43.388 mm (1.7062 in)
b
36.959 ~ 37.059 mm
(1.4551 ~ 1.4590 in)
<Limit>:
36.840 mm (1.4504 in)
Exhaust
a
43.129 ~ 43.229 mm
(1.6980 ~ 1.7019 in)
<Limit>:
42.983 mm (1.6922 in)
b
37.007 ~ 37.107 mm
(1.4570 ~ 1.4609 in)
<Limit>:
36.886 mm (1.4522 in)
Camshaft runout limit
0.040 mm (0.0016 in)
CHECKING THE DECOMPRESSION
SYSTEM
1. Check:
• decompression system
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a. Check the decompression system with the
camshaft sprocket installed on and the
decompressor pin installed in the camshaft.
b. Check that the decompressor lever pin 1
projects from the camshaft.
c. Check that the decompressor cam
2
moves smoothly.
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2
1
ROCKER ARMS AND CAMSHAFT