Yamaha YBR125ED 2005 Service Manual page 200

VALVES AND VALVE SPRINGS
c. After installing the valve guide, bore the
NOTE:
_
After replacing the valve guide, reface the
valve seat.
L
3. Eliminate:
4. Check:
5. Measure:
5 - 24
valve guide with the valve guide reamer 3
to obtain the proper valve-stem-to-valve-
guide clearance.
Valve guide remover (ø5)
90890-04097, YM-04097
Valve guide installer (ø5)
90890-04098, YM-04098
Valve guide reamer (ø5)
90890-04099, YM-04099
LLL L LLL L L LLL L L LLL
• carbon deposits
(from the valve face and valve seat)
• valve face
Pitting/wear → Grind the valve face.
• valve stem end
Mushroom shape or diameter larger than
the body of the valve stem → Replace the
valve.
• valve margin thickness a
Out of specification → Replace the valve.
Valve margin thickness
Intake
0.40 ~ 0.80 mm
(0.0157 ~ 0.0315 in)
Exhaust
0.80 ~ 1.20 mm
(0.0315 ~ 0.0472 in)
ENG
L L LLL L L LLL L LLL