Linhai 2004 ATV 260 Service Manual page 71

CHAPTER 3A ENGINE
3. Measure:
Valve seat width ○
a
Out of specification → Reface the valve seat.
Valve seat width:
<Limit:1.6mm>
<Limit:1.6mm>
Measurement step:
Apply Mechanic's blueing dye (Dykem)
the valve face.
Install the valve into the cylinder head.
Press the valve through the valve guide and
onto the valve seat to make a clear pattern.
Measure the valve seat width. Where the valve
seat and valve face made contact, blueing will
have been removed.
If the valve seat is too wide, too narrow, or the
seat is not centered, the valve seat must be
replaced.
4. Lap:
Valve face
Valve seat
NOTE:
After replacing the valve seat, valve and valve
guide, the valve seat and valve face should be
lapped.
Lapping steps:
Apply a coarse lapping com pound ○
valve face.
CAUTION:
Do not let compound enter the gap between the
valve stem and the guide.
Apply molybdenum disulfide oil to the valve
stem.
Install the valve into the cylinder head.
Turn the valve until the valve face and valve
seat are evenly polished, then clean off al com
pound.
260/ 300 / 400 cc
Intake:
0.9-1.1mm
Exhaust:
0.9-1.1mm
a
to
to the
ATV SERVICE MANUAL09.0
CHAPTER 3 ENGINE PAGE. 3A- 32