Yamaha 2003 YZ450FR Owner's Service Manual page 131

1
3
CAMSHAFTS
6. Remove:
2
Clips
G
Exhaust camshaft 1
G
Intake camshaft 2
G
NOTE:
Attach a wire 3 to the timing chain to prevent
it from falling into the crankcase.
INSPECTION
Camshaft
1. Inspect:
Cam lobes
G
Pitting/scratches/blue discoloration →
Replace.
2. Measure:
Cam lobes length a and b
G
Out of specification → Replace.
3. Measure:
Runout (camshaft)
G
Out of specification → Replace.
4 - 24
ENG
Cam lobes length:
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)
Runout (camshaft):
Less than 0.03 mm (0.0012 in)