DAELIM NS125III Service Manual page 103

Cylinder Head/Valve
Use a 55 cutter to make minor repairs on the
inside.
Use a 45 cutter to make adjustment within the
level of prescribed width.
Apply a light coating of prussian blue to the
valve seat. Gently strike the valve with a valve
guide reamer to check the status of contact,
without turning the valve.
If the contact surface is too high, grind the
surface with a 37 cutter, and finish to the
prescribed width with a 45 cutter.
If the contact surface is too low, grind the surface
with a 55 cutter, and finish to the prescribed
width with a 45 cutter.
9-10
Too high
Too low
55
Seat width
45
37
55