Leakage Testing The Crankcase - Stihl 009 User Manual

STIHL 009, 010, 011
Removing gasket web at inlet port
Then insert and tighten down the
flat head screws to a torque of
4 - 5 Nm (0.4 - 0.5 kpm).
Reassemble all remaining parts by
reversing the disassembly
sequence. Carry out crankcase
leakage test (3.8) and check
ignition timing (4.5.2) before final
assembly.
Important: The web of the
crankcase gasket across the inlet
port must becut away before
fitting the diaphragm.
3.8 Leakage Testing the
Crankcase
Top:
Carburetor and crankcase tester 1106 850 2900
Bottom:
Vacuum pump 0000 850 3500
Defective oil seals and gaskets or
accucracks in castings are the usual
causes of leaks. Such faults allow
supplementary air to enter the engine
and upset the fuel-air mixture.
This makes adjustment of the
prescribed idle speed difficult or even
impossible. Moreover, the transition
from idle speed to part or full throttle
is not smooth.
The crankcase can be checked
rately for leaks with the carburetor/
crankcase tester and the vacuum
pump.
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