STIHL FS 56 RC TRIMMER WONT IDLE

smitty88

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I HAVE A STIHL FS 56 RC TRIMMER THAT WILL IDLE FOR ABOUT 10-15 SECONDS THEN DIE. IT WILL RUN FINE AS LONG AS YOU GIVE IT THROTTLE. I PUT ON A NEW CARB, FUEL LINES AND A FILTER BUT STILL WONT IDLE LONG..ANY SUGGESTIONS?
 

upupandaway

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Find which hose goes into the tank to the fuel filter. Disconnect this hose from the carb and slowly prime the carb until fuel comes out the hose. When it comes out, stop priming and let it sit. Does it drop or stay? drop = leaking grommets or hose or gas cap.

There are other causes but I would say are much more unlikely. Try this first.
 

smitty88

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Find which hose goes into the tank to the fuel filter. Disconnect this hose from the carb and slowly prime the carb until fuel comes out the hose. When it comes out, stop priming and let it sit. Does it drop or stay? drop = leaking grommets or hose or gas cap.

There are other causes but I would say are much more unlikely. Try this first.

ok thanks for your response, I will give that a shot tomorrow..
 

Dan1129

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Check you spark spark ignitor screen for carbon buildup located in the muffler. Take socket and pull that out should be a screen located on it when pulled out. use a propane torch heat the screen red hot and the allow to cool. Take a wire brush and clean all carbon off should be see through. Let us know
 

nhyrum

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if neither of the above recommendations help, you may need to increase your idle speed or adjust your low jet setting. I, personally remove the spark arrestor, among other things in the muffler of my fs 45, and honestly all of my 2-strokes, except chainsaws, those keep the arrestor
 

Dan1129

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Plus on that note removin the spark arrestor just make it sound meaner !
 

nhyrum

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Plus on that note removin the spark arrestor just make it sound meaner !

You should hear my fs45. The muffler is basically a resonator now, it's hollow. Sounds like a 150cc dirt bike
 

nhyrum

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does it sputter out and die? or just die like you flipped the kill switch?

another tip. have a can of carb and choke cleaner handy, and keep the air box open. start it, and when it starts to die give it a small dribble of the carb cleaner. if it revves back up, you have a fuel supply issue, not enough fuel is making it out if the carb, into the engine. if it kills it, you either sprayed too much, or youre getting too much fuel into the cylinder.

Does your carb have 3 adjustment screws? if not, I'd recommend getting one.
 

smitty88

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I finally got around to messing with the stihl again, took carb and fuel lines off and cleaned real good again and in the process I found that the tank grommet was not seated correctly.. it now runs and idles like it should... thanks for the replies!!!! :thumbsup:
 
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