6.3 Oil Seals - Stihl MS 210 Service Manual

6.2.3 Vacuum Test
Oil seals tend to fail when subjected
to a vacuum, i.e. the sealing lip lifts
away from the crankshaft during the
piston's induction stroke because
there is no internal counterpressure.
An additional test can be carried out
with the vacuum pump to detect this
kind of fault.
– Carry out the preparations –
b 6.2.1.
: Connect suction hose of vacuum
pump 0000 850 3501 to test
flange nipple.
3
1
: Close the vent screw (1) on the
pump.
: Operate the lever (2) until
pressure gauge (3) indicates a
vacuum of 0.5 bar (7.25 psi).
26
If the vacuum reading remains
constant, or rises to no more than
0.3 bar (4.25 psi) within 20 seconds,
it can be assumed that the oil seals
are in good condition.
However, if the pressure continues
to rise (reduced vacuum in the
engine housing), the oil seals must
be replaced.
– After finishing the test, open the
vent screw and disconnect the
hose.
– Remove the test flange.
– Install the carburetor –
b 11.2.2.
– Remove the flange.
– Remove the sealing plate.
– Install the muffler – b 6.1.
2
6.3 Oil Seals
It is not necessary to disassemble
the complete engine housing if only
the oil seals have to be replaced.
Clutch side:
– Remove the clutch – b 5.3.
– Remove the oil pump – b 10.5.
: Ease the retaining ring out of the
crankshaft.
MS 210, MS 230, MS 250