Yamaha YP125R - Checking the Rocker Arms and Rocker Arm Shafts

CAMSHAFT (YP125R)
5-16
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EAS37P1011
CHECKING THE ROCKER ARMS AND
ROCKER ARM SHAFTS
The following procedure applies to all of the
rocker arms and rocker arm shafts.
1. Check:
• Rocker arm
• Rocker arm roller “1”
Damage/wear → Replace.
2. Check:
• Rocker arm shaft
Blue discoloration/excessive wear/pit-
ting/scratches → Replace or check the lubri-
cation system.
3. Measure:
• Rocker arm inside diameter “a”
Out of specification → Replace.
4. Measure:
• Rocker arm shaft outside diameter “a”
Out of specification → Replace.
5. Calculate:
• Rocker-arm-to-rocker-arm-shaft clearance
T
IP
Calculate the clearance by subtracting the rock-
er arm shaft outside diameter from the rocker
arm inside diameter.
Out of specification → Replace the defective
part(s).
2
A
2
B
1
Rocker arm inside diameter
9.985–10.000 mm (0.3931–
0.3937 in)
Limit
10.015 mm (0.3943 in)
Rocker arm shaft outside diame-
ter
9.966–9.976 mm (0.3924–0.3928
in)
Limit
9.940 mm (0.3913 in)
Rocker-arm-to-rocker-arm-shaft
clearance
0.009–0.034 mm (0.0004–0.0013
in)
Limit
0.075 mm (0.0030 in)