Leakage Testing - Stihl MS 441 Manual

1
: Fit heat shield (1) and line it up
with the recesses (arrows)
engaging the sealing face of the
cylinder.
1
: Fit gasket (1) between the bumps
(arrows) so that it is held in place.
1
– Carefully slide muffler (1) into
position.
: Slide the holes (arrows) into the
stud bolts to secure the muffler in
place.
MS 441, MS 441 C
– Fit screws (arrows) and check
that gasket is correctly
positioned.
: Tighten down screws (arrows).
1 2
– To ensure that the muffler is
correctly secured and tight,
tighten down screw (1) with 5 Nm
and screw (2) with 10 Nm, then
tighten screw (1) further to
10 Nm.
: Screw on the nuts (arrows) and
tighten them securely.
– Press home plugs.
– Tightening torques, b 3.5.
8.2

Leakage testing

Defective oil seals and gaskets or
cracks in castings cause leaks.
Such faults allow supplementary air
to enter the engine and thus impair
the fuel-air mixture.
This makes adjustment of the
specified idle speed difficult or even
impossible.
It also prevents a smooth transition
from idle speed to part or full
throttle.
Always test under vacuum first and
then continue at gauge pressure.
The power unit can be thoroughly
checked for leaks under vacuum
and at gauge pressure with the
pump 0000 850 1300.
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