Yamaha MBK MW125 2014 Service Manual page 226

Valve-stem-to-valve-guide clear-
ance (intake)
0.010–0.037 mm (0.0004–0.0015
in)
Limit
0.080 mm (0.0032 in)
Valve-stem-to-valve-guide clear-
ance (exhaust)
0.025–0.052 mm (0.0010–0.0020
in)
Limit
0.110 mm (0.0043 in)
2. Replace:
• Valve guide
TIP
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.
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a. Remove the valve guide with the valve guide
remover "1".
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VALVES AND VALVE SPRINGS
b. Install the new valve guide with the valve
guide installer "2" and valve guide remover
"1".
Valve guide position
a. Valve guide position
c. After installing the valve guide, bore the valve
guide with the valve guide reamer "3" to ob-
tain the proper valve-stem-to-valve-guide
clearance.
TIP
After replacing the valve guide, reface the valve
seat.
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5-23
Intake
9.55–9.95 mm (0.376–0.392 in)
Exhaust
9.55–9.95 mm (0.376–0.392 in)
Valve guide remover (ø5)
90890-04097
Valve guide remover (5.0 mm)
YM-04097
Valve guide installer (ø5)
90890-04098
Valve guide installer (5.0 mm)
YM-04098
Valve guide reamer (ø5)
90890-04099
Valve guide reamer (5.0 mm)
YM-04099
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