Yamaha 2002 TDM900 Service Manual page 274

VALVES AND VALVE SPRINGS
a. Remove the valve guide with the valve guide
remover 1 .
b. Install the new valve guide with the valve
guide installer 2 and valve guide remover
1 .
c. After installing the valve guide, bore the
valve guide with the 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:
S carbon deposits
(from the valve face and valve seat)
4. Check:
S valve face
Pitting/wear ! Grind the valve face.
S valve stem end
Mushroom shape or diameter larger than the
body of the valve stem ! Replace the valve.
5. Measure:
S valve margin thickness a
Out of specification ! Replace the valve.
6. Measure:
S valve stem runout
Out of specification ! Replace the valve.
NOTE:
S When installing a new valve, always replace
the valve guide.
S If the valve is removed or replaced, always re-
place the oil seal.
5-25
ENG
Valve guide remover (5.5 mm)
90890-04016
Valve guide installer (5.5 mm)
90890-04015
Valve guide reamer (5.5 mm)
90890-01196
Valve margin thickness
0.8 X 1.2 mm
Valve stem runout
0.01 mm