Checking The Valve Seats - Orion AGB-21G Service Manual

CAMSHAFT /VALVES AND VALVE SPRINGS
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3. Eliminate:
carbon deposits
(from the valve face and valve seat)
4. Check:
valve face
Pitting/wear Grind the valve face.
valve stem end
Mushroom shape or diameter larger than the
body of the valve stem
5. Measure:
valve margin thickness a
Out of specification
Valve margin thickness
0.95 mm
0.65
6. Measure:
valve stem runout
Out of specification
NOTE:
When installing a new valve, always replace
the valve guide.
If the valve is removed or replaced, always re-
place the oil seal.
Valve stem runout
Limit: 0.03 mm

CHECKING THE VALVE SEATS

The following procedure applies to all of the
valves and valve seats.
1. Eliminate:
carbon deposits
(from the valve face and valve seat)
2. Check:
valve seat
Pitting/wear Replace the cylinder head.
3. Measure:
valve seat width a
Out of specification
head.
Valve seat width
Intake: 0.8
Limit: 1.6 mm
Exhaust: 0.8
Limit: 1.6 mm
Replace the valve.
Replace the valve.
Replace the valve.
Replace the cylinder
1.2mm
1.2mm