Suzuki Madura GV700GL Service Manual page 63

3-33 ENGINE SERVICING
NOTE:
The valve seat contact area must be inspected
after each cut
• Insert the solid pilot
CD
with a slight rotation.
Seat the pilot snugly. Install the 45° cutter,
attachment and T handle.
• Using the 45° cutter, descale and cleanup the
seat with one or two turns.
• Inspect the seat by the previously described seat
width measurement procedure. If the seat is
pitted or burned, additional seat conditioning
with the 45° cutter is required.
NOTE:
Cut only the mm1mum amount necessary
from the seat to prevent the possibility of the
valve stem becoming too close to the cam
for correct valve clearance adjustment.
If the contact area is too high on the valve, or if it
is too wide, use a 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. 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 during the first few
seconds of engine operation.
• Clean and assemble the head and valve com-
ponents. 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.
NOTE:
Always use extreme caution when handling
gasoline.
Contact area too high
and too wide on face of
valve
Contact area too I ow
and too narrow on face
of valve