Yamaha F30B 2018, Service Manual

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Camshaft and valve
Checking the valve spring
1. Measure:
• Free length “a”
Below specification

Replace.
2. Measure:
• Tilt “a”
Above specification

Replace.
Checking the valve
1. Check:
• Valve face
Pitted/worn

Replace.
2. Measure:
• Margin thickness “a”
Out of specification

Replace.
3. Measure:
• Stem diameter “a”
Below specification

Replace.
Free length IN
39.85 mm (1.57 in)
Limit
37.86 mm (1.49 in)
Free length EX
39.85 mm (1.57 in)
Limit
37.86 mm (1.49 in)
Tilt limit IN
1.7 mm (0.07 in)
Tilt limit EX
1.7 mm (0.07 in)
a
a
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)
Diameter IN
5.475–5.490 mm (0.2156–
0.2161 in)
Limit
5.445 mm (0.2144 in)
Diameter EX
5.460–5.475 mm (0.2150–
0.2156 in)
Limit
5.430 mm (0.2138 in)
a
a