SELVA MARINE Kingfish 25, Руководство по обслуживанию

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7-44
7
5. Adjust the valve seat contact width to
specification using a 45° cutter.
b
Previous contact width
c
Specified contact width
6. Check the valve seat contact area of the
valve. See “Checking the valve seat” (7-
42).
Example:
• If the valve seat contact area is too wide
and situated in the center of the valve face,
cut the top edge of the valve seat using a
30° cutter, and then cut the bottom edge
using a 60° cutter to center the area and set
its width.
b
Previous contact width
• If the valve seat contact area is too narrow
and situated near the top edge of the valve
face, cut the top edge of the valve seat
using a 30° cutter to center the area, and
then set its width using a 45° cutter.
b
Previous contact width
• If the valve seat contact area is too narrow
and situated near the bottom edge of the
valve face, cut the bottom edge of the valve
seat using a 60° cutter to center the area,
and then set its width using a 45° cutter.
b
Previous contact width
7. After refacing the valve seat to the speci-
fied contact width, apply a thin, even
layer of lapping compound onto the valve
seat, and then lap the valve using the
special service tool.
NOTICE: Do not get
the lapping compound on the valve
stem and valve guide.
8. Recheck the valve seat contact area of
the valve. See “Checking the valve seat”
(7-42).
Checking the rocker arm and rocker
arm shaft
1. Check the rocker arm, rocker arm shaft,
and contact surface
a
of the rocker arm.
2. Measure the rocker arm inside diameter
b
and rocker arm shaft diameter
c
.
45˚
b
c
30˚
60˚
b
30˚
b
Valve lapper
1
: 90890-04101
60˚
b
1
Camshaft and valve