Yamaha XVS250 2001 Service Manual page 203

VALVES AND VALVE SPRINGS
Out of specification  Replace the valve
guide.
2. Replace.
D valve guide
NOTE:
To ease valve guide removal and installation,
and to maintain the correct fit, heat the cylinder
head to 100_C (212_F) in an oven.
a. Remove the valve guide with a valve guide
remover 1 .
b. Install the new valve guide with a valve guide
installer 2 and valve guide remover 1 .
c. After installing the valve guide, bore the
valve guide with a valve guide reamer 3 to
obtain the proper valve-stem-to-valve-guide
clearance.
NOTE:
After replacing the valve guide, reface the valve
seat.
3. Eliminate:
D carbon deposits
(from the valve face and valve seat)
4. Check:
D valve face
Pitting/wear  Grind the valve face.
D valve stem end
Mushroom shape or diameter larger than the
body of the valve stem  Replace the valve.
5-22
ENG
Valve-stem-to-valve-guide
clearance
Intake 0.010 0.037 mm
<Limit>: 0.08 mm
Exhaust 0.025 0.052 mm
<Limit>: 0.1 mm
Valve guide remover (5.0 mm)
90890-04097
Valve guide installer (5.0 mm)
90890-04098