Servicing The Carburetor; Metering Diaphragm - Stihl MS 341 Shop Manual

3
– Push the fuel line with nipple onto
the carburetor's elbow connector.
: 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
approx. 0.8 bar (80 kPa).
If this pressure remains constant,
the carburetor is airtight. However, if
it drops, there are two possible
causes:
1. The 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 12.3.2
2. Metering diaphragm damaged,
replace if necessary – b 12.3.1
– After completing the test, open
the vent screw (1) and pull the
fuel line off the carburetor.
– Push the fuel hose onto the
elbow connector.
– Install the carburetor – b 12.2.1
Reassemble all other parts in the
reverse sequence.
MS 341, MS 361, MS 361 C
12.3

Servicing the Carburetor

12.3.1 Metering Diaphragm

2
1
– Remove the carburetor –
b 12.2.1
: Take out the screws (arrows).
: Remove the end cover (1).
: Remove the metering diaphragm
and gasket (arrow) from the
carburetor body or end cover.
: Carefully separate the diaphragm
and gasket.
If the gasket and diaphragm are
stuck to the carburetor, remove
them very carefully.
The diaphragm material is
1
subjected to continuous alternating
stresses and eventually shows
signs of fatigue, i.e. the diaphragm
distorts and swells and has to be
replaced.
Reassemble in the reverse
sequence.
: Place the gasket on the
carburetor body so that the tab
(arrow) points towards the
adjusting screws.
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