Suzuki GSF650S Service Manual page 70

3-34 ENGINE
• Seat the pilot snugly. Install the 45° cutter 2, attachment 3
and T-handle 4.
INITIAL SEAT CUT
• Using the 45° cutter, descale and clean up the seat. Rotate
the cutter one or two turns.
• Measure the valve seat width W after every cut.
• If the valve seat is pitted or burned, use the 45° cutter to con-
dition the seat some more.
NOTE:
Cut only the minimum amount necessary from the seat to pre-
vent the possibility of the valve stem becoming too close to the
rocker arm for correct valve contact angle.
TOP NARROWING CUT
• 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.
45˚
Contact area too high and too
wide on face of valve
15˚