Checking The Rocker Arms And Rocker Arm Shafts - Yamaha MIO Service Manual

CAMSHAFT
EAS00206
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
Damage/wear → Replace.
2. Check:
• rocker arm shaft
Blue discoloration/excessive wear/pitting/
scratches → Replace or check the lubrica-
tion system.
3. Measure:
• rocker arm inside diameter
Out of specification → Replace.
Rocker arm inside diameter
10.000 ~ 10.015 mm
(0.3937 ~ 0.3943 in)
<Limit>: 10.030 mm (0.3949 in)
4. Measure:
• rocker arm shaft outside diameter
Out of specification → Replace.
Rocker arm shaft outside diame-
ter
9.981 ~ 9.991 mm
(0.3930 ~ 0.3933 in)
<Limit>: 9.950 mm (0.3917 in)
5. Calculate:
• rocker-arm-to-rocker-arm-shaft clearance
NOTE:
_
Calculate the clearance by subtracting the
rocker arm shaft outside diameter from the
rocker arm inside diameter.
Above 0.08 mm (0.0031 in) → Replace the
defective part(s).
Rocker-arm-to-rocker-arm-shaft
clearance
0.009 ~ 0.034 mm
(0.0004 ~ 0.0013 in)
<Limit>: 0.08 mm (0.0031 in)
4 - 20
ENG