Yamaha F50D, Руководство по обслуживанию

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Power unit
7-35
POWR
TIP:
9
Apply engine oil to the inner surface of the
valve guide.
9
Turn the valve guide reamer clockwise to
ream the valve guide.
9
Do not turn the reamer counterclockwise
when removing it.
9
Make sure to clean the valve guide after
reaming it.
4. Measure the valve guide inside diameter.
Checking the valve seat
1. Eliminate carbon deposits from the
valves.
2. Apply a thin, even layer of Mechanic’s
blueing dye (Dykem) onto the valve seat.
3. Lap the valve slowly on the valve seat
with the special service tool
1
.
4. Measure the valve seat contact width
a
where the blueing dye is 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.
Replace the valve guide if the valve seat
contact width is uneven.
Refacing the valve seat
After every lapping procedure, make sure
to clean off any remaining lapping com-
pound from the cylinder head and the
valves.
1. Reface the valve seat with the valve seat
cutter.
Valve guide reamer
5
: 90890-06804
Valve guide inside diameter:
5.500–5.512 mm (0.2165–0.2170 in)
Valve lapper
1
: 90890-04101
5
2
1
Valve seat contact width
a
:
Intake:
0.900–1.100 mm (0.0354–0.0433 in)
Exhaust:
0.900–1.100 mm (0.0354–0.0433 in)
a