Valveseat Inspection/Refacing - Honda Hawk GT NT650 1988 Service Manual

CYLINDER HEADIVALVES
VALVESEAT INSPECTION/REFACING
Clean the intake and exhaust valves thoroughly to remove
carbon deposits.
Apply a light coating of Prussian Blue to each valve seat. Lap
each valve and seat using a rubber hose or other hand-lapping
tool.
Remove and inspect each valve.
CAUTION
(1) VALVE
The valves cannot be ground. If a valve face is burned or badly
worn or
if
it contacts the seat unevenly, replace the valve.
Inspect the width of each valve seat.
STANDARD:
0.9-1.1
mm
(0.035-0.043
in)
SERVICE LIMIT:
1.5
mm
(0.06
in)
If the seat is too wide. too narrow or has low spots, the seat
must be ground.
VALVE SEAT CUTTERS
Honda Valve Seat Cutters, grinder or equivalent valve seat
refacing equipment are recommended to correct a worn valve
seat.
NOTE
• Follow the refacer manufacturer's operating instructions.
IN: 07780-0014000
(30
</»
EX: 07780-0014100
(37.5
</»
C
Zl)32
0
IN: 07780-0012100 (28 </>1
EX: 07780-0012300 (35
</»
VALVE SEAT REFACING
Use a 45 degree cutter to remove any roughness or irregulari-
ties from the seat.
NOTE
Reface the seat with a
45
degree cutter when a valve guide
is replaced.
9-12
IN: 07780-0010200 (27.5
</»
EX: 07780-0010400 (35 </>1
(1) ROUGHNESS/IRREGULARITIES