Small Engines (Lawn Mowers, etc.): stihl fs 25 4, speed needles, stihl fs

Question
Hi Fred,the motor runs for approx 30 secs and wont restart is there some kind of
safety cut out? or is it possible her is an ignition problem? have tried 2 or 3
times with same outcome can you help? many thanks

Answer
Not a safety system. Doesn't sound like ignition.  It could be an electronic spark advance issue.  You would have to get a new ignition pack from Sthil.  

When it dies does it dye rich or lean.  Rich is from to much fuel and lean is not enough.  If it dies rich the engine is getting too much fuel and flooding out.  This can be caused by the inlet needle not seating, repair with a carb kit.  If it dies lean like it is running out of fuel check the vent cap in the fuel cap.  Check the primer and fuel lines and be sure they are not switched. if you can, reset the high and low speed needles.  They are covered by caulk.  Back out the high speed screw at lease 2 turns and try to run.  DO NOT lean out the high speed to get more RPM;s. Readjust the screws and re-caulk.   Maybe it is the little screen in the body of the carburetor.  That is the side the fuel goes in.  Check the in-tank fuel filter too.  Try these suggestions and let me know.