Valve Seat Reconditioning - Honda GX690 Workshop Manual

VALVE SEAT RECONDITIONING

Valve seat cutters/grinders or equivalent valve seat
refacing equipment are recommended to correct worn
valve seats.
Using a 45° cutter remove enough material to produce
a smooth and concentric seat.
TOOLS:
Cutter holder 5.5 mm (1)
Seat cutter 33 mm (45° IN) (2)
Seat cutter 27.5 mm (45° EX) (2) 07780-0010200
Turn the cutter clockwise, never counterclockwise.
Continue to turn the cutter as you lift it from the valve
seat.
Use the 32° and 60° cutters to adjust the valve seat so
that it contacts the middle of the valve face.
The 32° cutter removes material from the top edge.
TOOLS:
Cutter holder 5.5 mm
Flat cutter 33 mm (32° IN)
Flat cutter 30 mm (32° EX)
The 60° cutter removes material from the bottom edge.
TOOLS:
Cutter holder 5.5 mm
Interior cutter 30 mm (60° IN)
Interior cutter 26 mm (60° EX) 07780-0014500
Be sure that the width of the finished valve seat is within
specification.
Make a light pass with 45° cutter to remove any
possible burrs at the edge of the seat.
TOOLS:
Cutter holder 5.5 mm
Seat cutter 33 mm (45° IN)
Seat cutter 27.5 mm (45° EX)
After resurfacing the seats, inspect for even valve
seating.
Apply Prussian Blue compound or erasable felt-tipped
marker ink to the valve seat. Insert the valve, and snap
it closed against its seat several times. Be sure the
valve does not rotate on the seat.
The seating surface, as shown by the transferred
marking compound, should have good contact all the
way around.
Thoroughly clean the cylinder to remove any cutting
residual.
07981-VA20101
07780-0010800
07981-VA20101
07780-0012900
07780-0012200
07981-VA20101
07780-0014000
07981-VA20101
07780-0010800
07780-0010200
(1)
CONTACT TO STANDARD
VALVE FACE
CONTACT TOO HIGH
VALVE FACE
VALVE
FACE
32°
CYLINDER
(2)
VALVE
FACE
60°
14-13