Suzuki GZ250 Service Manual page 65

3-29 ENGINE
• When installing the solid pilot
the pilot snugly. Install the 45° cutter, attachment and
T-handle.
• Using the 45° cutter, descale and clean up the seat. Ro-
tate the cutter one or two turns.
• Measure the valve seat width after every cut. If the valve
seat is pitted or burned, use the 45° cutter to condition
the seat same more.
NOTE:
Cut only the minimum amount necessary from the seat to
prevent the possibility of the valve stem becoming too
close to the rocker arm for correct valve contact angle.
If the contact area is too high on the valve, or If it is too
wide, use the 15° cutter to lower and narrow the contact
area.
If the contact area is too low or too narrow, use the 45°
cutter to raise and widen the contact area.
• After the desired seat position and width is achieved, use
the 45° cutter very lightly to clean up any burrs caused
by the previous cutting operations.
CAUTION
DO NOT use lapping compound after the final cut
is made. The finished valve seat should have a
velvety smooth finish and not a highly polished or
shiny finish. This will provide a soft surface for
the final seating of the valve which will occur dur-
ing the first few seconds of engine operation.
Clean and assemble the head and valve components.
Fill the intake and exhaust ports with gasoline to check
for leaks. If any leaks occur, inspect the valve seat and
face for burrs or other things that could prevent the valve
from sealing.
WARNING
Always use extreme caution when handling gaso-
line.
NOTE:
After servicing the valve seats, be sure to check the valve
clearance after the cylinder has been reinstalled. (See pp.
, rotate it slightly. Seat
Contact area too high and too wide
on face of valve
2-4 to -6.)