Yamaha WaveRunner VXR VX1800A, Service Manual

Page: 143 / 318

Valve and valve spring
5-52
3. Adjust the top edge of the valve seat con-
tact width using a 30° cutter.
4. Adjust the bottom edge of the valve seat
contact width using a 60° cutter.
5. Adjust the valve seat contact width to
specification using a 45° cutter.
6. Check the valve seat contact area of the
valve “Valve seat check” (5-50).
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° cut-
ter, and then cut the bottom edge using a 60°
cutter to center the area and set its 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.
a. Slag or rough surface
a. Previous contact width
a. Previous contact width
a
45
30
a
60
a
a. Previous contact width
b. Specified contact width
a. Previous contact width
a. Previous contact width
45
a
b
a
30
60
30
a