KEEWAY ATV300, User Manual

Page: 40 / 110

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6-7 Valve Seat Inspection and Service
Clean up all carbon deposits onto intake and
exhaust valves.
Apply with emery slightly onto valve contact
face. Grind valve seat with a rubber hose or
other manual grinding tool.
Caution
Remove the valve and check its contact face
Caution
Valve seat inspection
If the valve seat is too width, narrow or rough,
corrects it.
Valve seat width
Service limit: 1.6mm
Check the contact condition of valve seat.
Valve seat grinding
The worn valve seat has to be ground with valve
seat chamfer cutter.
Refer to operation manual of the valve seat
chamfer cutter.
Use 45° valve seat chamfer cutter to cut any
rough or uneven surface from valve seat.
Caution
Use 32° cutter to cut a quarter upper parts out.
˙ ˙ ˙ ˙
Do not let emery enter into between valve
stem and valve guide.
˙
˙ ˙
˙
Clean up the emery after corrected, and
apply with engine oil onto contact faces of
valve and valve seat.
Replace the valve with new one if valve seal
is roughness, wear out, or incomplete
contacted with valve seat.
After valve guide had been replaced, it has
to be ground with 45° valve seal chamfer
cutter to correct its seat face.
Valve seat width