Yamaha F100A - Service Points; Valve Inspection

5-27
POWR
E
VALVES
SERVICE POINTS
Valve inspection
1. Inspect:
● Valve
Damage/warpage → Replace.
2. Measure:
● Margin thickness a
Out of specification → Replace.
Margin thickness:
IN: 0.45 ~ 0.65 mm
(0.018 ~ 0.026 in)
EX: 0.65 ~ 0.85 mm
(0.026 ~ 0.033 in)
a
3. Measure:
● Valve stem diameter a
Out of specification → Replace.
Valve stem diameter:
IN: 5.975 ~ 5.990 mm
(0.235 ~ 0.236 in)
EX: 5.960 ~ 5.975 mm
(0.2346 ~ 0.2352 in)
a
4. Measure:
● Valve stem runout
Out of specification → Replace.
NOTE:
The valve guide, valve seal, and valve
should be replaced as a set.
Valve stem runout limit:
IN and EX: 0.03 mm (0.001 in)