hanging idle?

Upon getting my dads bike up and running, it is now having an issue with a hanging idle. I have checked for air leaks and have found none. All the jets were replaced with new ones, and i am completely lost with what to try checking next. 

Throttle cable binds, sticking throttle tube, carb slide binding/ notch worn where it contacts the idle screw.

Upon getting my dads bike up and running, it is now having an issue with a hanging idle. I have checked for air leaks and have found none. All the jets were replaced with new ones, and i am completely lost with what to try checking next. 


...and bike, model, make, year, hours, tuning, .............?

...and bike, model, make, year, hours, tuning, .............?

Oh yeah..that could be helpful..sorry about that. Its a 2006 250SX-F (KTM). Was a Boysen Factory bike so has all the boysen stuff, power shot bowl, power now or whatever, I dont know hours and i dont remeber what jets i put in. they are all new and are the same from when it wass running good last. hours are unknown

Hanging idle is usually your pilot circuit being set up incorrectly.

Your fuel screw is too far out which makes it want to stall and your idle screw is wound in too far to compensate for the rich fuel screw.

When you back off the throttle there is too much fuel/air still available so it wants to stay revving.


back your idle off till it almost stalls, then slowly (1/4 turn at a time) wind in your fuel screw till the revs climb back up (blip throttle a bit in between to test for hanging idle). Should run much better.

this is assuming the correct pilot jet is installed.

So, if was running well once before with the jetting you have, the problem is NOT jetting.


Have you adjusted your fuel screw?

As suggested above check your slide! I did everything and I mean everything for months but check my slide and sure enough it was worn. look at it closely as you twist the throttle and if there is anything other than smooth movement this is most likely your problem. Its a tough decision to make to replace, I was lucky and had bought a spare carb cheap

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