Yamaha FT50C - Checking the Valve Guides; Replacing the Valve Guides

62Y5A11
5-26
1
2
3
4
5
6
7
8
9
3. Measure the valve stem diameter
b
.
Replace if out of specification.
4. Measure the valve stem runout. Replace
if out of specification.
Checking the valve guides
1. Measure the valve guide inside diameter
a
. Replace if out of specification.
Replacing the valve guides
1. Remove the valve guide
1
by striking
the special service tool from the combus-
tion chamber side.
Valve margin thickness
a
:
Intake:
0.6–1.0 mm (0.024–0.039 in)
Exhaust:
0.7–1.1 mm (0.028–0.043 in)
Valve stem diameter
b
:
Intake:
5.48–5.49 mm (0.2157–0.2161 in)
Exhaust:
5.46–5.47 mm (0.2150–0.2153 in)
Valve stem runout:
Intake: 0.03 mm (0.0012 in)
Exhaust: 0.03 mm (0.0012 in)
Valve guide inside diameter limit
a
:
5.50–5.51 mm (0.2165–0.2169 in)
Valve guide remover/installer:
90890-06801
Cylinder head