# Stihl BR400 only runs on half choke!



## ELACESAR (Jun 3, 2009)

Hello all again i just wanted to let you know that i was able to start my Stihl after rebuilding the carb and it has incredible power but for it to stay running i have to play with the choke back and forth until it will stay running!! I made sure i changed everything in the carb cause there was plenty of varnish from the old gas so i am at a standstill now... Any help will be appreciated.. Thanks beforehand..


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## bgbass (Jan 11, 2008)

assuming that the rebuild is right and there are no air leaks then it could be running to lean try adjusting the mixture screw


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## ELACESAR (Jun 3, 2009)

Thanks for the help and where should i check for the air leaks besides the gaskets.. Thanks


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## rotti1968 (Apr 26, 2009)

crank seals, intake,cylinder bolts etc. The base setting on that carb should 1 turn each on high and low speed screws. Then adjust from there,also make sure your idle screw is adjusted correctly.


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## geogrubb (Jul 28, 2006)

While it is running spray carb/brake parts cleaner along all mating surfaces behind the carb and along the crankcase, if the engine tempo changes you have found a leak. If you replaced the metering arm when you were installing the carb kit, I would suggest using the old one, unless it was very worn, as it has the proper height setting. Have a good one. Geo


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## ELACESAR (Jun 3, 2009)

Thanks so much guys I will work on it tonight!!


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## week0019 (Oct 22, 2009)

Did you ever figure this out?

Mine is acting similar. It ran fine last fall (a little weak at full throttle, but ok considering it's age) but now it will only run on 1/2 to full choke.

I've heard these are sensitive to exhaust clogging. I fogged the cylinder heavily last fall and wonder if when I started it up this fall all that oil went through the exhaust and plugged it up. I may try to remove the exhaust completly for a trial and see if this problem goes away, if so I'll get a new exhaust. 

Also, I've tried tinkering with the carb. I don't think it's dirty but want to rule that out. If I'm going to soak it in carb cleaner I need to figure out how to remove the fuel nipple and choke knob. These didn't seem to want to come off. Anyone know how to remove these?

Thanks!


P.S I took the air filter off and no change so I don't think a dirty air filter is the problem.


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## ELACESAR (Jun 3, 2009)

*Stihl BR400*

I cleaned out the mixture screw holes and its working much better.. Great Blower


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## week0019 (Oct 22, 2009)

ELACESAR said:


> I cleaned out the mixture screw holes and its working much better.. Great Blower


Thanks. I've been messing with it and cleaned out the carb but now I lost the spring that controls the needle so hopefully when I get another one I can get it to run right.


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