Replacing The Valve Guides - Yamaha F150A Service Manual

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 and 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:
90890-06801
2. Install a new valve guide 2 by striking
the special service tool from the cam-
shaft side until the valve guide installer
3 contacts the cylinder head.
3
2
NOTE:
Apply engine oil to the surface of the new
valve guide.
63P3F11
1
S69J5790
E
S69J5800
Valve guide remover/installer:
90890-06801
Valve guide installer: 90890-06810
3. Insert the special service tool into the
valve guide 2, and then ream the valve
guide.
NOTE:
• Turn the valve guide reamer clockwise to
ream the valve guide.
• Do not turn the reamer counterclockwise
when removing the reamer.
Valve guide reamer: 90890-06804
4. Measure the valve guide inside diameter.
Valve guide inside diameter:
5.504–5.522 mm
(0.2167–0.2174 in)
Cylinder head
1
2
3
4
5
6
7
8
9
5-30