Removing And Installing; Servicing The Carburetor; Metering Diaphragm - Stihl BR 500 Service Manual

3
: Close the vent screw (1) on the
rubber bulb (2) and pump air into
the carburetor until the pressure
gauge (3) shows a reading of
about 0.8 bar (80 kPa).
If this pressure remains constant,
the carburetor is airtight. However, if
it drops, there are two possible
causes:
1. Inlet needle is not sealing foreign
matter in valve seat or sealing cone
of inlet needle is damaged or inlet
control lever sticking), remove to
clean, b 6.3.2
2. Metering diaphragm is damaged,
replace if necessary, b 6.3.1
– After completing the test, open
the vent screw (1) and pull the
hose off the carburetor.
– Push the fuel hose onto the
elbow connector.
– Install the carburetor, b 6.2.2
Install all other parts in the reverse
sequence.
20
6.2.2

Removing and Installing

2
1
1
– Remove the filter housing, b 6.1
: Disconnect the fuel hose (1).
: Disconnect the impulse hose (2).
1
: Disconnect nipple (1) from the
slotted pin (2) on the throttle
lever.
– Check flange for damage and
replace if necessary.
Install in the reverse sequence.
Always install new gaskets.
6.3
6.3.1
2
– Remove the carburetor, b 6.2.2
: Take out the screws (arrows).
: Remove the end cover (1).
2
: Remove the metering diaphragm
Carefully separate the diaphragm
and gasket.
If the gasket and diaphragm are
stuck to the carburetor, remove and
separate them very carefully.

Servicing the Carburetor

Metering Diaphragm

1
and gasket (arrow) from the
carburetor body or end cover.
BR 500, BR 550, BR 600