SELVA MARINE Wahoo 15 Service Manual page 141

CAUTION:
Do not over cut the valve seat. Be sure to
turn the cutter evenly downward at a pres-
sure of 40–50 N (4–5 kgf, 8.8–11 lbf) to
prevent chatter marks.
3. Use a 30° cutter to adjust the contact
width of the top edge of the valve seat.
30˚
b Previous contact width
4. Use a 60° cutter to adjust the contact
width of the bottom edge of the valve
seat.
b Previous contact width
5. Use a 45° cutter to adjust the contact
width of the valve seat to specification.
b Previous contact width
c Specified contact width
6AG3J11
b
S6AG5J60J
b
60˚
S6AG5J70J
b
c
45˚
S6AG5J80J
6. Check the valve seat contact area of the
valve.
NOTE:
To check the valve seat contact area, see
"Checking the valve seat" (5-40).
7. If the valve seat contact area is too wide
and situated in the center of the valve
face, use a 30° cutter to cut the top edge
of the valve seat and a 60° cutter to cut
the bottom edge to center the area and
set its width.
30˚
b
b Previous contact width
8. If the valve seat contact area is too nar-
row and situated near the top edge of the
valve face, use a 30° cutter to cut the top
edge of the valve seat, and then use a
45° cutter to center the area and set its
width.
30˚
b
b Previous contact width
Cylinder head
1
2
3
4
60˚
S6AG5J30J
5
6
7
8
S6AG5J40J
9
5-42