Yamaha 2003 YFZ450S, Service Manual

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4 - 12
ENG
CAMSHAFTS
6. Remove:
• exhaust camshaft
1
• intake camshaft
2
• clips
NOTE:
To prevent the timing chain from falling into the
crankcase, fasten it with a wire
3
.
1
2
3
CHECKING THE CAMSHAFTS
1.
Check:
• camshaft lobes
Pitting/scratches/blue discoloration
→
Replace the camshaft.
2. Measure:
• camshaft lobe dimensions
a
and
b
Out of specification
→
Replace the cam-
shaft.
Camshaft lobe dimensions
Intake
a
31.200 ~ 31.300 mm
(1.2283 ~ 1.2323 in)
<Limit>: 31.100 mm
(1.2244 in)
b
22.550 ~ 22.650 mm
(0.8878 ~ 0.8917 in)
<Limit>: 22.450 mm
(0.8839 in)
Exhaust
a
30.950 ~ 31.050 mm
(1.2185 ~ 1.2224 in)
<Limit>: 30.850 mm
(1.2146 in)
b
22.494 ~ 22.594 mm
(0.8856 ~ 0.8895 in)
<Limit>: 22.394 mm
(0.8817 in)
3. Measure:
• camshaft runout
Out of specification
→
Replace.
Camshaft runout limit
0.03 mm (0.0012 in)