Preparations; 5.6 Crankcase Leakage - Stihl 034 Series User Manual

– Slide the oil seal, open side
facing the crankcase, over the
ignition end of the crankshaft.
Use press sleeve 1121 893 2400
to press home oil seal until sleeve
butts against the crankcase.
Important:
It is essential to observe the correct
installed depth of the oil seal to
achieve a proper seal. Always use
the press sleeve for this operation.
– Reassemble all other parts in the
reverse sequence.
034, 036, 036 QS
5.6 Crankcase Leakage Test
Defective oil seals and gaskets or
cracks in castings are the usual
causes of leaks. Such faults allow
supplementary air to enter the
engine and thus upset the fuel-air
mixture.
This makes adjustment of the
prescribed idle speed difficult, if not
impossible.
Moreover, the transition from idle
speed to part or full throttle is not
smooth.
The crankcase can be checked
thoroughly for leaks with the
carburetor and crankcase tester
1106 850 2905 and the vacuum
pump 0000 850 3501.
5.6.1

Preparations

– Remove the shroud from the
cylinder - see 4.3.
– Take out the muffler upper casing
mounting screws and remove the
upper casing - see 5.1.
Loosen the muffler lower casing
mounting screws about half way.
Fit sealing plate 0000 855 8106,
from above and narrow end first,
between the muffler lower casing
and cylinder exhaust port.
Note:
The sealing plate must completely
fill the space between the two
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