Valve Seat
Inspect the intake and exhaust valve seats, and correct the contact surfaces with a valve seat cutter if they are defective or when valve guides are replaced.
Valve seat width W:
Intake
Standard 0.6 - 1.4 mm (0.024 - 0.055 in)
Exhaust
Standard 1.2 - 1.8 mm (0.047 - 0.071 in)