Valve Seat - Yamaha ttr230 Service Manual

INSPECTION AND REPAIR
NOTE:
Rotate the head some turns in order to avoid
excessive removal of material only on one
side.

VALVE SEAT

1. Remove:
• Carbon fouling
(from the valve and seat)
2. Inspect:
• Valve seat
Wear => Grind the seat.
3. Measure:
• Valve seat width a
Out of specification => Grind
the seat.
Valve seat width:
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Measurement steps:
• Apply blue mechanic paint on the valve
face.
• Install the valve on the head.
• Press the valve through the guide to the
valve seat.
• Measure the valve seat width.
• If the valve seat width is too thin or too
thick or off-center, the valve seat should
be redone.
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4-26
ENGINE
Intake:
0.9~1.1 mm (0.035 ~0.043 in)
Exhaust:
0.9~1.1 mm (0.035 ~0.043 in)