Honda EU65is Mode D'emploi page 398

cap.13 EU65is 6500is 07.12.17 5:05 PM ページ13-7
3) Using a 45° cutter, remove enough material to produce a
smooth and concentric seat.
Turn the cutter clockwise, never counterclockwise.
Continue to turn the cutter as you lift it from the valve seat.
4) Use the 30° and 60° cutters to narrow and adjust the valve
seat so that it contacts the middle of the valve face.
The 30° cutter removes material from the top edge (contact
too high).
The 60° cutter removes material from the bottom edge
(contact too low). Be sure that the width of the finished
valve seat is within specification.
5) Make a light pass with 45° cutter to remove any possible
burrs at the edge of the seat.
6) After resurfacing the seat, inspect for even valve seating.
Apply Prussian Blue compound or erasable felt-tipped
marker ink to the valve face. 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.
7) Lap the valves into their seats, using a hand valve lapper
and lapping compound (commercially available).
8) To avoid severe engine damage, be sure to remove all
lapping compound from the engine before reassembly.
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[1] CONTACT TOO HIGH
[2] CONTACT TOO LOW
[1]
VALVE SEAT
WIDTH