Carburetor - Stihl FS 240 Service Manual

3.6

Carburetor

Problem
Carburetor floods; engine stalls
Poor acceleration, version without
M-Tronic
... All versions
... Versions with M-Tronic
14
Cause
Inlet needle not sealing
– Foreign matter in valve seat or
cone
Inlet needle worn
Inlet control lever sticking on
spindle
Helical spring not located on nipple
of inlet control lever
Perforated disc on diaphragm is
deformed and presses constantly
against the inlet control lever
Metering diaphragm is deformed
Low speed screw "too lean"
High speed screw "too lean"
Inlet needle sticking to valve seat
Diaphragm gasket leaking
Metering diaphragm damaged or
shrunk
Tank vent faulty
Leak in fuel line between tank and
carburetor
Parts in carburetor or M-Tronic
wiring harness defective
FS 240 C, FS 260 C, FS 360 C, FS 410 C, FS 460 C-M
Remedy
Remove and clean inlet needle or
clean carburetor
Replace inlet needle
Examine control lever, replace if
necessary
Remove the inlet control lever and
refit it correctly
Replace metering diaphragm
Replace metering diaphragm
Check basic carburetor setting,
correct if necessary
Check basic carburetor setting,
correct if necessary
Remove inlet needle, clean and
refit
Replace diaphragm gasket
Replace metering diaphragm
Replace tank vent
Seal connections or replace line
Carry out M-Tronic diagnosis, if
necessary, replace carburetor or
M-Tronic wiring harness