Suzuki DR 125 Service Manual page 58

3-22 ENGINE
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)
& 09900-20606: Dial gauge (1/100 mm)
09900-20701: Magnetic stand
09900-21304: V-block (100 mm)
VALVE STEM DEFLECTION
Lift the valve about 10 mm (0.4 in) from the valve seat. Measure
the valve stem deflection in two directions, "X" and "Y", perpen-
dicular to each other. Position the dial gauge as shown. If the
deflection exceeds the service limit, then determine whether the
valve or the guide should be replaced with a new one.
$ Valve stem deflection
Service Limit:
Intake and exhaust valves: 0.35 mm (0.014 in)
& 09900-20606: Dial gauge (1/100 mm)
09900-20701: Magnetic stand
VALVE STEM WEAR
Measure the valve stem O.D. using the micrometer. If it is out of
specification, replace the valve with a new one. If the valve stem
O.D. is within specification but the valve stem deflection is not,
replace the valve guide. After replacing the valve or valve guide,
re-check the deflection.
$ 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 replaced, refer to the valve guide ser-
vicing steps below.
VALVE GUIDE SERVICE
• Remove the valve guide using the special tool.
& 09916-44910: Valve guide remover/installer
NOTE:
* Discard the removed valve guide subassemblies.
* Only oversized valve guides are available as replacement
parts.