Honda GX240RT2 Service And Repair Manual page 148

gx240ut2_gx270ut2_gx340ut2_gx390ut2
The 30° cutter removes material from the top edge
(contact too high).
TOOLS:
Solid pilot bar, 6.6 mm
Cutter, 30 x 45 degrees
The 60° cutter removes material from the bottom edge
(contact too low).
TOOLS:
Solid pilot bar, 6.6 mm
Cutter, 60 degree
Be sure that the width of the finished valve seat is within
specification.
STANDARD: 1.0 – 1.2 mm (0.04 – 0.05 in)
SERVICE LIMIT: 2.0 mm (0.08 in)
Make a light pass with the 45° cutter to remove any
possible burrs at the edge of the seat.
TOOLS:
Solid pilot bar, 6.6 mm
Cutter, 30 x 45 degrees
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 head to remove all
cutting residue.
Lap the valves into their seats, using a commercially
available valve lapper and lapping compound.
After lapping, wash all residual compound off the
cylinder head and valve.
• Do not push the valve against the seat with force
during lapping. Apply a light pass with the valve
lapper.
• Avoid lapping the valve in the same position as it
causes uneven wear. Lap the valve by turning the
lapper slowly.
• Take care not to allow the lapping compound to
enter the gap between the stem and guide.
Adjust the valve clearance after assembly
CONTACT OK
NWY100-6.60
NWYCU128
NWY100-6.60
NWYCU114
CONTACT TOO HIGH
VALVE FACE
NWY100-6.60
NWYCU128
(page 3-12).
CYLINDER HEAD/VALVES
VALVE FACE
CONTACT TOO LOW
VALVE FACE
VALVE FACE
VALVE FACE
32°
VALVE LAPPER
LIL21100
(Commercially
available)
60°