Valve Seat Inspection - Yamaha EF3000iSE Service Manual

VALVE SEAT INSPECTION

1. Remove carbon deposits from the valve
face and valve seat.
2. Apply
Mechanic's blueing dye (Dykem) to the
valve face.
3. Insert the valve into the valve guide and
use a valve lapper to contact the valve
face with the valve seat.
NOTE:
Do not rotate the valve while the valve face is
contacting the valve seat.
4. Measure:
• Valve face contact width a
Make sure that the contact width along
the entire valve face is within specifica-
tions.
Valve face contact width (intake
SVU3240J
and exhaust):
Out of specification/rough/eccentric
wear → Replace.
5. Measure:
• Valve seat contact width a
Make sure that the contact width along
the entire valve seat is within specifica-
tions.
Valve seat contact width (intake
and exhaust):
SVU3250J
Out of specification/rough/eccentric
wear → Replace.
3-31
ENG
VALVE
a small amount
0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
Limit: 1.6 mm (0.0630 in)
0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
Limit: 1.6 mm (0.0630 in)
of coarse