Yamaha Rhino 450 YXR45FAV Service Manual page 152

CAMSHAFT, ROCKER ARMS AND VALVES
2. Check:
• rocker arms
• rocker arm shafts
Damage/wear → Replace.
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a. Check the two contact areas on the rocker
arms for signs of abnormal wear.
1) Rocker arm shaft hole
2) Camshaft lobe contact surface
Excessive wear → Replace.
b. Check the surface of the rocker arm shafts.
Blue discoloration/pitting/scratches →
Replace/check lubrication.
c. Measure the inside diameter a of the
rocker arm holes.
Out of specification → Replace.
Rocker arm inside diameter
12.000 ~ 12.018 mm
(0.4724 ~ 0.4731 in)
<Limit>: 12.078 mm (0.4755 in)
d. Measure the outside diameter b of the
rocker arm shafts.
Out of specification → Replace.
Rocker arm shaft outside diame-
ter
11.981 ~ 11.991 mm
(0.4717 ~ 0.4721 in)
<Limit>: 11.951 mm (0.4705 in)
e. Calculate the clearance by subtracting the
rocker arm shaft outside diameter from the
rocker arm inside diameter.
Out of specification → Replace the defec-
tive part(s).
Rocker arm to rocker arm shaft
clearance
0.009 ~ 0.037 mm
(0.0004 ~ 0.0015 in)
<Limit>: 0.080 mm (0.003 in)
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ENG
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