Checking The Valve Spring; Checking The Valve - Yamaha F30B 2018 Service Manual

Checking the valve spring

1. Measure:
• Free length "a"
Below specification  Replace.
a
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)
2. Measure:
• Tilt "a"
Above specification  Replace.
Tilt limit IN
1.7 mm (0.07 in)
Tilt limit EX
1.7 mm (0.07 in)
a

Checking the valve

1. Check:
• Valve face
Pitted/worn  Replace.
2. Measure:
• Margin thickness "a"
Out of specification  Replace.
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)
3. Measure:
• Stem diameter "a"
Below specification  Replace.
a
Diameter IN
5.475–5.490
0.2161 in)
Limit
5.445 mm (0.2144 in)
Diameter EX
5.460–5.475
0.2156 in)
Limit
5.430 mm (0.2138 in)
7-33
Camshaft and valve
a
mm (0.2156–
mm (0.2150–