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crf 250x bog issues

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I have a bog on my crf 250 when the throttle is cracked open suddenly. I have installed a 42 slow jet, raised needle three notches, and installed everything from a 130, 140 150 and a 160 main, with no change

Today, I just turned my airscrew all of the way in, and the bog pretty much went away. I turned it out 1/4 turn, and it works great. I still have a 160 main, and clip on third notch, and 42 slow jet. Why would turning in the airscrew fix the bog? Did this richen the mixture, or lean it? I think the screw should be out more than 1/4 turns. It use to be two turns out, and I never tried turning it in more than 1-1/2 turns before I assume that I need a different airscrew, but which direction should I go.

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You may be getting too much fuel with your current pilot jet. I'd go with one pilot jet smaller. That way you'll probably be more than 1/4 turn out, but with the same effect, and more adjustability.

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Thanks Tim

You would never guess what my problem was. I went to order a leaner fuel screw, and noticed that it came with a "o" ring on it. I rushed home and checked mine, and the "o" ring was not there. I replaced the "o" ring, and the bike is a monster now. It has never worked so good from idle to the mid-range. Very crisp and responsive. I do not think that it ever had the "o" ring in it from the factory, as it always bogged down low.

Wade

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