KDX not running great... maybe jetting?

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searle7
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KDX not running great... maybe jetting?

Post by searle7 »

I just purchased a 2002 KDX 200 with a Gnarly woods pipe. Took it for the first trail ride today. It ran okay but my brothers KDX which is stock seems to run better. I think it might be the jetting.

The bike has had all the fluids changed last week. It doesn't seem to run really strong. My riding area is southeast Idaho where it 5,000 to 9,000 feet and 75 F. My jetting specs are
155MJ
48 MJ
I didn't check the needle position but after doing some research it seems might be jetted way rich for my altitude. For being a KDX with a pipe it runs almost the same as my brothers stock KDX.

Any input or advice would be appreciated.
Last edited by searle7 on 03:50 pm Sep 02 2014, edited 1 time in total.
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Julien D
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Re: KDX not running great... maybe jetting?

Post by Julien D »

Sounds like stock jets, assuming that you mean 155MJ and 48 pilot, not 148.... lol. You should be able to go down on those jets quite a bit at that elevation. Do you have the airbox lid removed / drilled? That helps get a little more airflow. It doesn't take long to run through the jetting process, and it's well worth it. There's a great how-to sticky in the jets and needles section.
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bufftester
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Re: KDX not running great... maybe jetting?

Post by bufftester »

With all the mods the stock jetting is going to be off (stock is already rich to start with). Follow the jetting guide to the letter and you'll be riding with a big old bug smeared smile!
searle7
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Re: KDX not running great... maybe jetting?

Post by searle7 »

Yes I meant a 48 PJ! Thanks for catching that. I plan on going through the jetting process and I hope that it makes a big difference! It would be nice to be somewhat close rather than go from 155,152,150,148,145 as I feel I will probably end up close to a 145 MJ and a pilot jet.

I just thought that someone could give me a good starting point cause I feel like my jetting is probably WAY too rich!

Also is there a specific needle that I should use? I'm guessing I have the stock needle but I will have to check. I hear all this talk of CEL and DEK needles and I don't know which would be the best.
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