Carburetor - Stihl MS 240 Instruction Manual

4.6

Carburetor

Condition
Carburetor floods; engine stalls
Poor acceleration
MS 240, MS 260, MS 260 C
Cause
Inlet needle not sealing
– foreign matter in valve seat or
cone
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
Metered diaphragm deformed
Setting of low speed screw too lean Check basic carburetor setting,
Setting of high speed screw too
lean
Inlet needle sticking to valve seat
Diaphragm gasket leaking
Metering diaphragm damaged or
shrunk
Impulse hose damaged or kinked
Tank vent faulty
Leak on fuel hose from tank to
carburetor
Remedy
Remove and clean the inlet needle,
clean the carburetor
Check inlet control lever, replace if
necessary
Remove the inlet control lever and
refit it correctly
Fit a new metering diaphragm
Fit a new metering diaphragm
correct if necessary
Check basic carburetor setting,
correct if necessary
Remove inlet needle, clean and
refit
Fit new diaphragm gasket
Fit a new metering diaphragm
Install new impulse hose
Replace tank vent
Seal connections or install new fuel
hose
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