Stihl BR 500 - Engine Management; Adjusting the Carburetor

23BR 500, BR 550, BR 600
– Carefully separate the diaphragm
and gasket.
– Inspect the diaphragm for
damage and wear, fit anew
gasket.
As a result of the alternating
stresses, the diaphragm material
and the inlet and outlet valves
eventually show signs of fatigue, i.e.
the diaphragm distorts and swells
and has to be replaced.
: Examine the fuel strainer (1) for
contamination and damage. If
necessary, use a needle to pull it
out of the carburetor body and
clean or replace.
Install in the reverse sequence.
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: Fit the diaphragm (1) and
gasket (2) on the carburetor body
so that contours (arrow) match.
– Place the end cover on the
carburetor.
The pump diaphragm and gasket
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are held in position by cast pegs on
the end cover.
– Fit the screw and tighten it down
firmly, b 3.4
Install all other parts in the reverse
sequence.
– Remove the carburetor, b 6.2.2
Wear safety glasses.
: Take out the screw (1).
: Remove the throttle lever (2).
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: Carefully remove the spring (1).
: Remove the sleeve (2).
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Note correct installed position of
throttle shutter.
: Take out the screw (1).
: Remove the throttle shutter (2).
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6.3.4 Accelerator Pump
RA_452_00_01_02.book Seite 23 Donnerstag, 16. Februar 2012 11:52 11