Stihl MS 650

15MS 650, MS 660
Condition Cause Remedy
Engine will not idle,
idle speed too high
Throttle shutter opened too wide by
idle speed screw (LA)
Set idle speed screw (LA) correctly
Throttle rod sticking Check and free off throttle rod
Oil seals/crankcase leaking Seal or replace oil seals/
crankcase
Engine stalls at idle speed Idle jet too rich or too lean Set low speed screw (L)
correctly
Setting of idle speed incorrect –
throttle shutter completely closed
Set idle speed screw (LA)
correctly
Small plastic plate in valve jet
does not close
Clean or renew valve jet
Idle jet bores or ports blocked Clean the carburetor