Refacing The Valve Seat - SELVA MARINE Blue Whale 250 EFI Service Manual

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 is uneven.
Valve seat contact width a:
Intake:
1.10–1.40 mm (0.043–0.055 in)
Exhaust:
1.40–1.70 mm (0.055–0.067 in)

Refacing the valve seat

1. Reface the valve seat with the valve seat
cutter.
6P23H11
Valve seat cutter holder:
90890-06316
Valve seat cutter:
30° (intake): 90890-06817
30° (exhaust): 90890-06326
45° (intake): 90890-06816
45° (exhaust): 90890-06325
60° (intake and exhaust):
90890-06324
Cylinder head
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