Yamaha F15MHX Manuel D'entretien page 232

POWR
a
CAMSHAFT AND VALVES
SERVICE POINTS
Valve inspection
1. Measure:
9 Valve guide inside diameter a
Out of specification → Replace the
valve guide.
Valve guide inside diameter:
5.500 ~ 5.512 mm
(0.2165 ~ 0.2170 in)
2. Measure:
9 Valve seat width b
Out of specification → Reface the
valve seat.
Valve seat width :
0.6 ~ 0.8 mm (0.02 ~ 0.03 in)
3. Measure:
9 Margin thickness c
Out of specification → Replace the
valve.
Margin thickness:
0.5~ 0.90 mm (0.020 ~ 0.035 in)
4. Measure:
9 Valve stem diameter d
Out of specification → Replace the
valve.
Diameter:
IN : 5.475 ~ 5.490 mm
(0.2155 ~ 0.2161 in)
EX: 5.460 ~ 5.475 mm
(0.2150 ~ 0.2156 in)
5-25
E