Yamaha Fazer, Service Manual

Page: 90 / 213

ENG
INSPECTION AND REPAIR:VALVE SEATS
4-16
4. Lap :
• Valve face
• Valve seat
NOTE :
After refacing the Valve Seat or replacing the
Valve, the Valve Seat and Valve Face should be
lapped.
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Measurement steps :
• Apply Mechanic’s blueing dye (Dykem) è to
the valve face.
• Install the Valve in the Cylinder Head
• Press the Valve through the Valve Guide and
onto the valve seat to make a clear pattern.
• Measure the Valve Seat width. Where the
Valve Seat and Valve Face made contact,
blueing will have been removed.
• If the Valve Seat is too wide, too narrow, or
the seat is not centered, the valve seat must
be refaced.
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VALVE SEATS
1. Remove :
• Carbon deposits from the Valve Face and
Valve Seat.
2. Inspect :
• Valve Seats
Pitting/wear Ÿ reface the valve seat.
3. Measure :
• Valve Seat width ç
Out of specification Ÿ Reface the Valve
Seat.
Valve seat width :
Intake :
0.9 ~ 1.1 mm
<Limit : 1.6 mm>
Exhaust :
0.9 ~ 1.1 mm
<Limit : 1.6 mm>