Sym SYM series, Руководство пользователя, Страница: 143 / 178

6. CYLINDER HEAD/VALVE SYM
6-10
Valve seat inspection
If the valve seat is too width, narrow or rough,
correct 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 grinded with
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 part
out.
Use 60° cutter to cut a quarter lower part out.
Remove the cutter and check new valve
seat.
Use 45° cutter to grind the valve seat to
specified width.
Caution
Grind valve seat again if necessary.
After valve guide had been replaced, it
has to be grinded with 45° valve seal
chamfer cutter to correct its seat face.
Make sure that all roughness and
uneven faces had been grinded.
Old valve seat width
60°
45°
1.0mm
45°
Roughness
32°
Old valve seat width