Valve Seat - Yamaha YFM250XL(C) Service Manual

4
INSPECTION AND REPAIR
3.Install:
Circlip 1 (new)
Valve guide 2 (new)
Use the Valve Guide Installer 3 with the
Valve Guide Remover 4.
Valve guide installer:
P/N. YM-04065-A, 90890-04065
Valve guide remover (6.0 mm):
P/N. YM-04064-A, 90890-04064
4.Bore valve guide 2 to obtain proper valve
stem clearance.
Use the Valve Guide Reamer 5 (6.0 mm)
Valve guide reamer (6.0 mm):
P/N. YM-04066, 90890-04066
NOTE:
Reface the valve seat after installing the
valve guide.

VALVE SEAT

1.Eliminate:
Carbon deposit
(from valve seat and valve face)
2.Inspect:
Valve seat
Pitting/Wear → Reface valve seat.
3.Measure:
Valve seat width
Out of specification → Reface valve seat.
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Measurement steps:
Apply the Mechanic's bluing dye 1
(Dykem) to the valve face.
Install the valve into the cylinder head.
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ENG