Yamaha EF2800i - Inverter Generator, Service Manual

Page: 43 / 103

3-15
ENG
VALVE
VALVE SEAT INSPECTION
1. Remove carbon deposits from the valve
face and valve seat.
2. Apply a small amount of coarse
mechanic's blueing dye (Dykem) to the
valve face.
3. Insert the vale 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.
Out of specification/rough/eccentric
wear
→
Replace.
Valve face contact width (intake
and exhaust):
0.7 mm (0.03 in)
Limit: 1.7 mm (0.067 in)
SVU3250
5. Measure:
• Valve seat contact width
a
Make sure that the contact width along
the entire valve seat is within specifica-
tions.
Out of specification/rough/eccentric
wear
→
Replace.
Valve seat contact width (intake
and exhaust) :
0.7 mm (0.03 in)
Limit: 1.7 mm (0.067 in)
SVU3260