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Lean idle problem? KTM 250sx

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Im having a problem with my jetting and have been trying to fix it for weeks. I have a 13 250sx that was just rebuilt top and bottom. I can't figure out what it is, it sounds lean in the bottom and when you rev it it'll reach power band no bog but when you let off it sounds as if its starving for gas (takes a little to get back to idle). Ive tried playing around with pilot jets I went from a 45 all the way up to 50 but that was too rich and the problem didnt go away so I went back down to a 48 and it still did it but was fine reaching rpms. Another Lean hint is that it is extremely pingy almost like the pipe is leaking but I checked placement and for leaks and found nothing. I tried needle clip position as well but that never helped. If you know anything about this leave it here! 

Thanks, Matt

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If it wasn't doing that before the rebuild,  I have the hardest time thinking that the jetting requirements changed.  I think you are still looking for an air leak.  Does your idle get affected by the air screw?

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2 hours ago, ossagp said:

If it wasn't doing that before the rebuild,  I have the hardest time thinking that the jetting requirements changed.  I think you are still looking for an air leak.  Does your idle get affected by the air screw?

Ive tried playing around with the air screw and it helps a little, but it did it before the rebuild 

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That changes things.  Sadly I don't have your rig (sadly because I would like to!).   Things like cable play or if you have a cable casing that is slightly stretched it can act like a spring,  and keep the slide from returning all the way immediately etc.  Usually the cutaway doesn't show up until you get just off of idle,  my 88 suzuki rm acted funny on rolloff and just lifting up until it got a slide change,  but that was to make it just a little leaner right there.  Airleaks behind the rotor have done some funny idling tricks on my other two strokes,  though not exactly as you described,  and yours I am sure got new seals on the build.  I have a friend who has the same year you do.  He put a flywheel on it,  and I liked it.  He put a Rekluse on it this winter.  He is thinking of taking the flywheel weight off now.   Easy to make a play bike out of that racer.  

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