Yamaha 2011 WR250FA Owner's Service Manual page 169

4. To secure the valve cotters onto the valve
stem, lightly tap the valve tip with a piece of
wood.
Hitting the valve tip with excessive force
could damage the valve.
5. Install:
• Adjusting pad "1"
• Valve lifter "2"
• Apply the molybdenum disulfide oil on the
valve stem end.
• Apply the engine oil on the valve lifters.
• Valve lifter must turn smoothly when rotated
with a finger.
• Be careful to reinstall valve lifters and pads in
their original place.
VALVES AND VALVE SPRINGS
5-36