ENGINE 3-27
VALVE STEM DEFLECTION
• Lift the valve about 10 mm (0.39 in) from the valve seat.
• Measure the valve stem deflection in two directions, perpen-
dicular to each other, by positioning the dial gauge as shown.
• If the deflection measured exceeds the limit, then determine
whether the valve or the guide should be replaced with a new
one.
[ 09900-20606: Dial gauge (1/100 mm)
09900-20701: Magnetic stand
Valve stem deflection (IN & EX):
Service Limit: 0.35 mm (0.014 in)
VALVE STEM WEAR
• If the valve stem is worn down to the limit, as measured with a
micrometer, replace the valve.
• If the stem is within the limit, then replace the guide.
• After replacing valve or guide, be sure to recheck the deflec-
tion.
[ 09900-20205: Micrometer (0 – 25 mm)
Valve stem O.D.:
Standard (IN): 4.475 – 4.490 mm (0.1762 – 0.1768 in)
(EX): 4.455 – 4.470 mm (0.1754 – 0.1760 in)
NOTE:
If valve guides have to be removed for replacement after
inspecting related parts, carry out the steps shown in valve
guide servicing.
VALVE STEM RUNOUT
• Support the valve using V-blocks and check its runout using
the dial gauge as shown.
• If the runout exceeds the service limit, replace the valve.
[ 09900-20606: Dial gauge (1/100 mm)
09900-20701: Magnetic stand
09900-21304: V-block set (100 mm)
Valve stem runout: Service Limit: 0.05 mm (0.002 in)
VALVE HEAD RADIAL RUNOUT
• Place the dial gauge at a right angle to the valve head face
and measure the valve head radial runout.
• If it measures more than the service limit, replace the valve.
Valve head radial runout:
Service Limit: 0.03 mm (0.001 in)
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