Yamaha YX600S Service Manual page 79

Id
INSPECTION AND REPAIR
ENG
I \i~I
•Valve seat is too narrow and right up near
valve margin (See "c" diagram).
Valve Seat Cutter Set Desired Result
Use
0° Cutter, first
to obtain correct seat
45° Cutter
width.
•Valve seat is too narrow and is located down
near the bottom edge of the valve face (See
"d" diagram).
Valve Seat Cutter Set Desired Result
60° Cutter, first to obtain correct seat
Use
45° Cutter
width.
NOTE: ~~~~~~~~~~~~~
Lap valve/valve seat assembly if:
•Valve face/valve seat are used or severely worn.
•Valve and valve guide has been replaced.
•Valve seat has been cut.
Valve/Valve Seat Assembly Lapping
1. Apply:
•Coarse lapping compound (Small amount)
(to valve face)
2. Position:
•Valve
(in cylinder head)
3. Rotate:
•Valve
Turn until valve and valve seat are evenly
polished, then clean off compound.
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