DAELIM ET-250 Service Manual page 52

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 val v e 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 too high, grind the valve seat with
32° cutter.
Then, grind the valve seat to specified width.
If the contact surface too low, grind the valve seat with
60° cutter.
Then, grind the valve seat to specified width.
Contact surface too high
Contact surface too low
Old valve seat width
60°
1.0mm
45°
Old valve seat width
32°
Old valve seat width
60°