Checking The Valve Guides; Replacing The Valve Guides - Yamaha F80BETL Service Manual

Valve stem diameter b:
Intake:
5.975–5.990 mm
(0.2352–0.2358 in)
Exhaust:
5.960–5.975 mm
(0.2346–0.2352 in)
4. Measure the valve stem runout. Replace
if above specification.
Valve stem runout limit:
0.01 mm (0.0004 in)

Checking the valve guides

NOTE:
Before checking the valve guide make sure
that the valve stem diameter is within specifi-
cation.
1. Measure the valve guide inside diameter
a.
6D93G11
a
Valve guide inside diameter a:
Intake and exhaust:
6.000–6.018 mm
(0.2362–0.2369 in)
2. Calculate the valve stem-to-valve guide
clearance as follows. Replace the valve
guide if out of specification.
Valve stem-to-valve guide clearance
= valve guide inside diameter – valve
stem diameter:
Intake:
0.010–0.043 mm
(0.0004–0.0017 in)
Exhaust:
0.025–0.058 mm
(0.0010–0.0023 in)

Replacing the valve guides

1. Remove the valve guide 1 by striking
the special service tool from the combus-
tion chamber side.
Valve guide remover/installer 5.9:
90890-04064
Cylinder head
1
2
S60C5450
3
4
5
6
7
8
9
5-28