Repair Of Carburetor - Stihl 009 User Manual

STIHL 009, 010, 011
8.5

Repair of Carburetor

Top:
Removing fuel pump end cover
Bottom:
Taking out the fuel strainer
It is advisable to check the service-
ability of the fuel pump whenever the
carburetor is removed for repair.
Unscrew the fuel pump end cover and
remove the gasket and pump
diaphragm. The end cover, gasket
and diaphragm are frequently stuck
together. If this is the case, take parti-
cular care when separating them. If
the fuel strainer in the pump side of
the carburetor body is dirty, it should
Removing metering chamber cover
be lifted out with a screwdriver and
washed in clean gasoline. Always
replace the fuel strainer if it shows
any signs of damage.
To disassemble the carburetor body,
unscrew the metering chamber cover
and remove the metering diaphragm
and gasket. This diaphragm and gas-
ket may also be stuck together and
must be separated carefully.
The diaphragms are the most
delicate parts of the carburetor. Due
to the continuous alternating stress
to which the diaphragms are
subjected, the material eventually
shows signs of fatigue - the
diaphragms distort and swell. When
this stage is reached the carburetor
can no longer function correctly and
the diaphragms must be replaced.
The inlet needle valve is located in a
Removing inlet needle
recess in the metering diaphragm
chamber. The inlet control lever with
spindle, helical spring and inlet
needle can be removed after
unscrewing the round head screw. If
an annular indentation is visible on
the cone of the inlet needle, it should
be replaced as it will no longer seal
properly. This is indicated by
constant flooding of the carburetor
although the needle is clean.
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