Stihl MS 240 Instruction Manual page 17

Condition
Engine will not idle, idle speed too
high
Engine stalls at idle speed
16
Cause
Throttle shutter opened too wide by
idle speed screw LA
Oil seals/crankcase leaking
Idle jet bores
or ports blocked
Setting of low speed screw too rich
or too lean
Setting of idle speed screw LA
incorrect – throttle shutter
completely closed
Tank vent faulty
Leak on fuel hose from tank to
carburetor
Remedy
Reset idle speed screw LA
correctly
Seal or replace oil seals/crankcase
Clean the carburetor
Reset low speed screw L correctly
Reset idle speed screw LA
correctly
Replace tank vent
Seal connections or install new fuel
hose
MS 240, MS 260, MS 260 C