Yamaha YZ250F(S) Owner's Service Manual page 202

VALVE CLEARANCE INSPECTION AND ADJUSTMENT
Install the new pads 3 and the valve lift-
G
ers 4.
NOTE:
Apply the engine oil on the valve lifters.
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Apply the molybdenum disulfide oil on the
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valve stem ends.
Valve lifter must turn smoothly when
G
rotated with a finger.
Be careful to reinstall valve lifters and
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pads in their original place.
Install the camshafts (exhaust and intake).
G
Refer to "CAMSHAFTS" section in the
CHAPTER 4.
3 - 22
INSP
ADJ