Suzuki DR-Z70 Service Manual page 57

3-25 ENGINE
VALVE STEM DEFLECTION
• Lift the valve about 10 mm 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, then determine
whether the valve or the guide should be replaced with a new
one.
Valve stem deflection:
Service Limit (IN. & EX.): 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, 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.
Valve stem O.D.:
Standard (IN.) : 4.960 – 4.975 mm (0.1953 – 0.1959 in)
(EX.): 4.945 – 4.960 mm (0.1947 – 0.1953 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. ( below)
VALVE GUIDE SERVICING
• Using the valve guide remover, drive the valve guide out
toward the intake or exhaust camshaft side.
09916-44310: Valve guide remover/installer
NOTE:
* Discard the removed valve guide subassemblies.
* Only oversized valve guides are available as replacement
parts. (Part No. 11115-02A70 (IN.), 11115-09470 (EX.))
• Re-finish the valve guide holes in cylinder head with the
reamer and handle.
09916-34580: Valve guide reamer (10.8 mm)
09916-34542: Reamer handle
When refinishing or removing the reamer from the
valve guide hole, always turn it clockwise.