Yamaha F75F - Checking the Valve; Checking the Valve Spring

Camshaft and valve
7-32
b. Check the cylinder head warpage us-
ing a straightedge “1” and a thickness
gauge “2” in 7 directions.
Checking the valve spring
1. Measure:
• Free length “a”
Below specification  Replace.
2. Measure:
• Tilt “a”
Above specification  Re
place.
Checking the valve
1. Check:
• Valve face
Pitted/worn  Replace.
2. Measure:
• M
argin thickness “a”
Out of specification  Replace.
Free length IN
40.69 mm (1.60 in)
Limit
38.66 mm (1.52 in)
Free length EX
40.69 mm (1.60 in)
Limit
38.66 mm (1.52 in)
2
1
a
Tilt limit IN
1.7 mm (0.07 in)
Tilt limit EX
1.7 mm (0.07 in)
Margin thickness IN
0.80–1.20 mm (0.0315–0.0472
in)
Margin thickness EX
1.00–1.40 mm (0.0394–0.0551
in)
a
a