Leakage Testing The Engine; Preparations - Stihl 029, 039 Service Manual

STIHL 029, 039
4.2 Leakage Testing
the Engine
Top:
Carburetor and crankcase tester
1106 850 2905
Bottom:
Vacuum pump 0000 850 3500
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 engine housing can be checked
accurately for leaks with the
carburetor and crankcase tester and
the vacuum pump.
4.2.1

Preparations

Top:
1 = Sealing plate 0000 855 8106
2 = Flange 1123 855 4200
3 = Sleeves 1127 851 8300
Bottom:
Sealing plate between
mounting screws
- Remove the muffler - see 4.1.
- Position the sealing plate
between the mounting screws.
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