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I'm working on a friends 2007 ktm sxf250 and the bike runs like crap, I completely disassemble the carb and set it in a cleaner over night. I took it out the next morning and cleaned all the jets and passages with pressurized air. I put everything back together and it still won't start. The only way to get the bike to start is by turning the idle all the way up and turning it back down, now that the bike is started and the idle stew is turned down, you got to constantly give gas to keep the think going. I took it out on a ride and the bike ran fine until you pull the clutch in, at this point the bike stalls without any hesitation. To start the bike I need to repeat the whole prosedure to get it started. I have another buddy with an 08' and his bike is extremely cold blooded and takes forever to warm up. I'm not sure if there's an issue with the carb or the bike just needs its sweat time to warm up. PLEASE HELP!

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1. You cannot soak these carbs in solvent. It destroys the inner seal. Same goes for 'real' carb cleaner, you just can't use it

2.  Your symptom is of a bad pilot circuit. There is a 90 degree bend above the pilot that partially clogs. Ream it with copper wire and some real solvent (sparingly)

3.  You have  to adjust the fuel screw correctly, or it will act strange. Start with a hot motor. Kill it. Set the fuel screw to 1 turn out. Start it up and lower the idle with idle screw. Now raise the idle back up using only the FUEL screw. You will find a spot with the idle is the smoothest. That is your sweet spot for that day. It will change every time the air density changes

4. If you damaged the body seal, you need to replace it. I would recommend sending the carb to Tokyo mods for that. It sounds like this is something you should let a pro do.

5. All FCR carbs on KTM's are delivered poorly tuned. A JD Jetting kit is the fastest way to getting close without guessing. You can fine tune from their.

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Thank you very much replying, the carb was completely disassembled to avoid the damage of seals, I poorly use the term soak, I used light amounts of cleaner and let it sit for a bit the cleaned it out, I went ahead and cleaned the pilot ciurcuit as instructed and with the help of my brother who's a mechanic at a ktm dealer, put the carb back together with the stock recommended jets. The bike was put back together and tuned and it starts and idles beautifully.

the bike runs nice around the track but we are still having a problem, same as before, when the clutch is pulled in and the bike dies completely, even if you try to give it gas, it's not bogging or anything, it almost seems like the clutch engages the kill switch. We are still having trouble but we no longer think it's the carb, anymore help?

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The clutch itself can only have one effect: drag. If the clutch is dragging badly, then yes, it can stall when you pull it in.

Otherwise, it's still just a tuning issue.

Have you done a correct fuel screw tuning? With a hot motor, lower the idle as low as it will go, then raise it back up with the fuel screw.

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