Checking The Valve Seat - Yamaha F225F Service Manual

Valve guide remover/installer b:
90890-06801
Valve guide installation height a:
11.300–11.700 mm
(0.4449–0.4606 in)
3. Insert the special service tool d into the
valve guide c, and then ream the valve
guide.
d
c
Valve guide reamer d: 90890-06804
TIP:
• To ream the valve guide, turn the special
service tool d clockwise.
• When removing the special service tool d,
do not turn it counterclockwise.
• After reaming the valve guide, make sure to
clean it.
4. Measure the valve guide inside diameter.
Valve guide inside diameter:
Intake and exhaust:
5.504–5.522 mm (0.2167–0.2174 in)

Checking the valve seat

1. Remove carbon deposits from the valve.
2. Apply a thin, even layer of Mechanic's
blueing dye (Dykem) onto the valve seat.
3. Push the valve lightly against the valve
seat using the special service tool a.
a
Valve lapper a: 90890-04101
4. Measure the valve seat contact width a
where the blueing dye adhered to the
valve face. Reface the valve seat if the
valve is not seated properly or if the valve
seat contact width is out of specification.
Check the valve guide if the valve seat
contact width is uneven.
a
Valve seat contact width a:
Intake:
1.100–1.400 mm (0.0433–0.0551 in)
Exhaust:
1.400–1.700 mm (0.0551–0.0669 in)
Cylinder head
0
1
2
3
4
5
6
7
8
9
10
A
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