3-40 ENGINE
VALVE FACE WEAR
Visually inspect each valve for wear of its seating face. Replace
any valve with an abnormally worn face. The thickness
T
decreases as the wear of the face advances.
Measure the thickness and, if the thickness is found to have
been reduced to the limit, replace it.
& Valve head thickness
T
Service Limit: 0.5 mm (0.02 in)
" 09900-20101: Vernier calipers
VALVE STEM DEFLECTION
Lift the valve about 10 mm (0.39 in) from the valve seat.
Measure the valve stem deflection in two directions, “X” and “Y”,
perpendicular to each other, by positioning the dial gauge as
shown. If the deflection measured exceeds the limit, (see below)
then determine whether the valve or the guide should be
replaced with a new one.
& Valve stem deflection (IN & EX)
Service Limit: 0.35 mm (0.014 in)
" 09900-20607: Dial gauge (1/100 mm)
09900-20701: Magnetic stand
VALVE STEM WEAR
If the valve stem is worn down to the limit, as measured with a
micrometer, where the clearance is found to be in excess of the
limit indicated, replace the valve; if the stem is within the limit,
then replace the guide. After replacing valve or guide, be sure to
recheck the clearance.
& Valve stem O.D.
Standard (IN) : 5.475 – 5.490 mm (0.2156 – 0.2161 in)
(EX): 5.455 – 5.470 mm (0.2148 – 0.2154 in)
" 09900-20205: Micrometer (0 – 25 mm)
NOTE:
If valve guides have to be removed for replacement after
inspecting related parts, carry out the steps shown in valve
guide servicing.
VALVE GUIDE SERVICING
• Using the valve guide remover, drive the valve guide out
toward the intake or exhaust camshaft side.
" 09916-44910: Valve guide remover/installer
NOTE:
* Discard the removed valve guide subassemblies.
* Only oversized valve guides are available as replacement
parts. (Part No.11115-32E70)
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