Yamaha F350B - Checking the Valve

7-51
Cylinder head
2. Measure:
• Spring tilt “a”
Above specification  Replace.
Checking the valve
1. Check:
• Valve face
Pitted/worn  Replace.
2. Measure:
• Margin thickness “a”
Below specification  Replace.
3. Measure:
• Stem diameter “a”
Below specification  Replace.
4. Measure:
• Stem runout
Above specification  Replace.
Free length IN
49.52 mm (1.95 in)
Limit
47.04 mm (1.85 in)
Free length EX
49.52 mm (1.95 in)
Limit
47.04 mm (1.85 in)
Tilt limit IN
1.7 mm (0.07 in)
Tilt limit EX
1.7 mm (0.07 in)
a
a
Margin thickness IN
0.55–0.95 mm (0.0217–0.0374
in)
Margin thickness EX
0.90–1.30 mm (0.0354–0.0512
in)
Diameter IN
5.477–5.492 mm (0.2156–
0.2162 in)
Limit
5.447 mm (0.2144 in)
Diameter EX
5.464–5.479 mm (0.2151–
0.2157 in)
Limit
5.434 mm (0.2139 in)
a