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My 02 cr 250 is over revving

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So ya. Noticed it last week when I was riding in woods. It doesn't do it from idle and it just revs out a bit then goes back down. So I cleaned the carb out. Lubed up the cable: replaced the needle in the throttle slide as well as the collar for the needle. The spring was a little worn however in the throttle slide but it's on back order. It's not an air leak as I did air leak test. I'm putting my main jet down to a 360 from a 380. I just put new rings in it and all head gasket kit. Took it out today and thing wiskey throttled me off a jump and was reving out so high. I just shit it down and drove it home. It's apart now..... Anyone have any ideas ? Throttle cable looks fine... Only thing I can think of honestly is the slide return spring in the carb is really weak... And not letting slide shut all the way.... Other than that I'm out of ideas. Any I put would be great. It's a brand new motor top to bottom with 40 hours on it now...

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That 360 mj sounds pretty lean. Have you changed any other part of the jetting ?

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What are your current conditions & jetting specs ?

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Jetting specs. All stock. Belray synthetic 2 t 40-1 mix. Carb is clean... I'm not overly concerned with the plugs here and there cuz I can just lean it out with air screw... I'm more concerned about the over revving. That just started last week. My inclination is to think it's a combination of the throttle cable seeing how it's a bit bent.. The weak slide spring..

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FYI - The MJ affects 3/4 - full throttle. That wouldn't be the main reason it's fouling plugs it's more likely in the 0 - 3/4 throttle position. The 01-03 mikuni runs well with a 380-400 mj at 0-1K ft elevation. Unless your over 100 deg. than the manual would call for a 360 mj..

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