Checking The Camshaft - Yamaha WR450F Owner's Service Manual

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CHECKING THE CAMSHAFT

EAS2GC1239
1. Check:
• Camshaft lobes
Blue discoloration/pitting/scratches  Re-
place the camshaft.
2. Measure:
• Camshaft lobe dimensions "A" and "B"
Out of specification  Replace the cam-
shaft.
Camshaft lobe dimensions
Lobe height (Intake)
37.630–37.730 mm (1.4815–
1.4854 in)
Limit
37.530 mm (1.4776 in)
Base circle diameter (intake)
27.950–28.050 mm (1.1004–
1.1043 in)
Limit
27.850 mm (1.0965 in)
Lobe height (Exhaust)
33.870–33.970 mm (1.3335–
1.3374 in)
Limit
33.770 mm (1.3295 in)
Base circle diameter (Exhaust)
24.711–24.811 mm (0.9729–
0.9768 in)
Limit
24.611 mm (0.9689 in)
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3. Measure:
• Camshaft runout
Out of specification  Replace.
4. Measure:
• Camshaft-journal-to-camshaft-cap clear-
ance
Out of specification  Measure the cam-
shaft journal diameter.
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a. Install the camshaft into the cylinder head.
b. Position a strip of Plastigauge® "1" onto the
camshaft journal as shown.
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CAMSHAFT
Camshaft runout limit
0.030 mm (0.0012 in)
Camshaft-journal-to-camshaft-
cap clearance
0.028–0.062 mm (0.0011–0.0024
in)
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