POWR
Power unit
5-31
67C3K11
3.
Measure the valve stem diameter
b
.
Replace the valve if out of specification.
4.
Measure the valve stem runout. Replace
the valve if above specification.
Checking the valve guide
NOTE:
Before checking a valve guide, make sure
that the valve stem diameter is within specifi-
cation.
1.
Measure the valve guide inside diameter
a
.
2.
Calculate the valve-stem-to-valve-guide
clearance as follows. Replace the valve
guide if out of specification.
Replacing the valve guide
1.
Remove the valve seal.
2.
Insert the special service tool
1
into the
combustion chamber end of the valve
guide
2
, and then strike the tool to drive
the guide out of the cylinder head.
Valve stem diameter
b
:
Intake:
5.475–5.490 mm
(0.2156–0.2161 in)
Exhaust:
5.460–5.475 mm
(0.2150–0.2156 in)
Valve stem runout limit:
Intake: 0.030 mm (0.0012 in)
Exhaust: 0.016 mm (0.0006 in)
Valve guide inside diameter
a
:
Intake and exhaust:
5.500–5.512 mm
(0.2165–0.2170 in)
Valve-stem-to-valve-guide clearance
= valve guide inside diameter – valve
stem diameter:
Intake:
0.010–0.037 mm
(0.0004–0.0015 in)
Exhaust:
0.025–0.052 mm
(0.0010–0.0020 in)
Valve guide remover/installer
1
:
90890-06801
S6AU5085
a
S67C5081
2
1
Summary of Contents for F30A
Page 1: ...F30A F40B SERVICE MANUAL 67C 28197 3K 11 ...
Page 4: ......
Page 26: ...GEN INFO General information 1 21 67C3K11 MEMO ...
Page 150: ...POWR Power unit 5 55 67C3K11 MEMO ...
Page 236: ...BRKT Bracket unit 7 55 67C3K11 MEMO ...
Page 282: ......
Page 283: ...YAMAHA MOTOR CO LTD Printed in China Aug 2007 1 2 1 CR E ...