Yamaha YZ250F(W) Owner's Service Manual page 310

1
3
5. Remove:
2
• 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 lobe
2. Measure:
• Cam lobe length a and b
3. Measure:
• Runout (camshaft)
4 - 25
CAMSHAFTS
Pitting/scratches/blue
Replace.
Out of specification → Replace.
Cam lobes length:
Intake:
a 30.246 ~ 30.346 mm
(1.1908 ~ 1.1947 in)
<Limit>: 30.146 mm
(1.1869 in)
b 22.45 ~ 22.55 mm
(0.8839 ~ 0.8878 in)
<Limit>: 22.35 mm
(0.8799 in)
Exhaust:
a 30.399 ~ 30.499 mm
(1.1968 ~ 1.2007 in)
<Limit>: 30.299 mm
(1.1929 in)
b 22.45 ~ 22.55 mm
(0.8839 ~ 0.8878 in)
<Limit>: 22.35 mm
(0.8799 in)
Out of specification → Replace.
Runout (camshaft):
Less than 0.03 mm (0.0012 in)
ENG
→
discoloration