14
MS 171, MS 181, MS 211
4.6
Carburetor
Condition
Cause
Remedy
Carburetor floods;
engine stalls
Inlet needle not sealing. Foreign
matter between valve seat and
cone or cone worn
Remove and clean or replace the
inlet needle, clean the carburetor,
replace inlet needle if necessary
Inlet control lever sticking on
spindle
Clean inlet control lever, replace if
necessary
Helical spring not located on nipple
of inlet control lever
Remove the inlet control lever and
refit it correctly
Perforated disc on diaphragm is
deformed and presses constantly
against the inlet control lever
Fit a new metering diaphragm
Poor acceleration
Setting of low speed screw too lean Check basic carburetor setting,
correct if necessary
High speed screw too rich
Check basic carburetor setting,
correct if necessary
Inlet needle sticking to valve seat
Remove inlet needle, clean and
refit
Diaphragm gasket leaking
Fit new diaphragm gasket
Metering diaphragm damaged or
shrunk
Fit new metering diaphragm
Manifold damaged
Install new manifold
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