Sym Quad Raider 600, Service Manual

Page: 79 / 247

6. CYLINDER HEAD/VALVE
6-12
Use 60° cutter to cut a quarter lower parts out.
Remove the cutter and check new valve seat.
Use 45° cutter to grind the valve seat to specified
width.
Caution
Make sure that all roughness and uneven faces
had been ground.
Grind valve seat again if necessary.
Coat the valve seat surface with red paint.
Install the valve through valve guide until the valve
contacting with valve seat, slightly press down the
valve but do not rotate it so that a seal track will be
created on contact surface.
Caution
The contact surfaces of valve and valve seat are
very important to the valve sealing capacity.
If the contact surface is too high, grind the valve
seat with 32° cutter.
Then, grind the valve seat to specified width.
If the contact surface is too low, grind the valve
seat with 60° cutter.
Then, grind the valve seat to specified width.
Old valve seat width
60°
1.0mm
60°
45°
32°
Old valve seat width
Contact surface too high
Old valve seat width
Contact surface too low
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