Yamaha BEARTRACKER YFM250XC, Service Manual

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ENG
INSPECTION AND REPAIR
●
Calculate the clearance by subtracting the
rocker-arm-shaft outside diameter from
the rocker-arm inside diameter.
Out of specification
→
Replace as a set.
Arm-to-shaft clearance =
Rocker arm inside diameter
a
–
Rocker arm shaft outside diameter
b
Arm-to-shaft clearance:
0.009 ~ 0.037 mm
(0.0004 ~ 0.0013 in)
<Limit>:
0.037 mm (0.0015 in)
2.Lubricate:
●
Rocker arms 1
●
Rocker arm shafts 2
●
Cam shaft 3 (cam lobe/journal)
3.Install:
●
Rocker arms
●
Rocker arms shafts
NOTE:
●
Thread hole of the rocker arm shaft
should be placed outside.
●
Install the shorter rocker arm shaft 1
(with O-ring 2 ) on the exhaust side and
the longer shaft 3 (with cutaway 4 ) on
the intake side.
●
Align the slit 4 on the rocker arm shaft
(intake) with the cylinder head bolt hole 5
and install the rocker arm shaft.
4.Install:
●
Camshaft 1
(to cylinder head)
NOTE:
The pin
2
on the end of the camshaft must
align with the timing mark
3
on the cylin-
der head.
Rocker arms/rocker arm shafts:
Molybdenum disulfide oil
Cam shaft:
SAE 10W30 motor oil
4