Valve Seat Refacing - DAELIM HISTORY 125 Service Manual

● Remove the valve and inspect the valve seat face.
● The valve seat contact should be within the specified
width and evenly all around the circumference.
If the valve seat width is not within specification,
reface the valve seat.
NOTE
·Valve faces and stem tips cannot be ground. If a valve
face or stem tip is rough, worn unevenly, or contacts
the seat improperly, the valve must be replaced.
● Measure the valve seat width.
STANDARD VALUE : 0.8 -1.0 mm
SERVICE LIMIT : 1.4 mm

VALVE SEAT REFACING

● Reface the worn valve seat by using valve seat cutters
and grinders.
NOTE
·Follow the refacer manufactuer's operating instructions.
·Reface the valve seat whenever the valve guide has
been replaced.
·Be careful not to grind the seat more than necessary.
● Using a 45 degree cutter, remove any roughness or
irregularities from the seat.
● Using a 37 degree cutter, remove ¼ of the existing
valve seat material.
CYLINDER HEAD / VALVES
37°
VALVE SEAT
45°
37°
ROUGHNESS
37°
55°
9-9