Yamaha 2001 YZ426F/LC Owner's Service Manual page 280

CAMSHAFTS
6. Remove:
Clips
Dowel pins
Exhaust camshaft 1
Intake camshaft 2
NOTE:
Attach a wire 3 to the timing chain to prevent
it from falling into the crankcase.
INSPECTION
Camshaft
1. Inspect:
Cam lobes
Pitting/scratches/blue discoloration →
Replace.
2. Measure:
Cam lobes length a and b
Out of specification → Replace.
Cam lobes length:
Intake:
a 31.7 ~ 31.8 mm
b 22.95 ~ 23.05 mm
Exhaust:
a 31.2 ~ 31.3 mm
b 22.95 ~ 23.05 mm
3. Measure:
Runout (camshaft)
Out of specification → Replace.
Runout (camshaft):
Less than 0.03 mm (0.0012 in)
4 - 22
ENG
(1.2480 ~ 1.2520 in)
<Limit>: 31.6 mm (1.244 in)
(0.9035 ~ 0.9075 in)
<Limit>: 22.85 mm (0.900 in)
(1.2283 ~ 1.2323 in)
<Limit>: 31.1 mm (1.224 in)
(0.9035 ~ 0.9075 in)
<Limit>: 22.85 mm (0.900 in)