Yamaha WR250FM service manual Inspection, Runout camshaft Less than 0.03 mm 0.0012

CAMSHAFTS

ENG

1 2

3

5.Remove:

•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

Pitting/scratches/blue discoloration → Replace.

2.Measure:

•Cam lobe length a and b

Out of specification → Replace.

Cam lobes length: Intake:

a 30.296 ~ 30.346 mm (1.1923 ~ 1.1947 in) <Limit>: 30.196 mm (1.1888 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)

3.Measure:

•Runout (camshaft)

Out of specification → Replace.

Runout (camshaft):

Less than 0.03 mm (0.0012 in)

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