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JD jetting kit for stock 2005 450x???

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I just ordered a jd kit for my low hour stock 2005 450x. I want it to run cooler for longevity hence the kit. I do not want to modify my air box or exhaust(good and quiet). Should I have any problems or have to make any other mods for the kit to work well with my stock bike? I have read about a number 50 leak jet but will that be required with my stock configuration and is that included with the kit?? The bike has great power for me stock but I know it gets hot!

dogdoc

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There are no leak jets included with the JD kit. The kit I bought for my Wr426 had 4 different size main jets, 2 needles, an extra needle clip, and a couple of o-rings for the AP.

The only mod I did was to remove the airbox lid as the directions indicated for my bike. I run a stock exhaust.

I couldn't be happier with how my bike runs after installing the JD kit.

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The instructions with the JD kit discuss derestricting the airbox and say that "...airbox opening need to be cut and open for this kit to perform properly."

The recommended settings may be affected if you don't. You can run the JD kit with a derestricted airbox, but stock muffler. JD kit has notes recommending a larger main with less restrictive exhaust.

Kit comes with two needles, red and blue. (stock is NCVU). The blue needle is used for cooler temps. Five main jets: 155, 160, 162,165, and 170 are supplied. (stock is #142). They also supply a thick and thin o-ring for the "O-ring mod" for earlier year carbs. No leak jets are supplied. :bonk:

JD it is not cheap. ~$70-$75. I'm not sure I would have gone this route with your preferences. Sounds like you are happy with the power and want to keep the exhaust and intake quiet with no mods? Your main goal is ensure that the bike is not running too lean to ensure good motor life? Maybe, a better solution would be to put in a main jet one size larger to richen the top end, drop your clip to richen middle throttle position, and put in a smaller leak jet for anti-bog when accelerating. Could also open up the idle mixture screw 1/2 turn to richen closed throttle position. Test ride after each mod to ensure the bike doesn't get a "stumbling" miss because it's too rich. With this approach, the jets are cheap, a few bucks a piece.

But since you have bought the JD kit, you may want to try one size smaller on the recommended main jet without de-restricting to see if it runs better than the recommended main jet size? Also, you don't have to go all the way and put holes in your airbox to de-restrict it. Just removing the "snorkle" should help, as stated in the post above.

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You could re-jet leaving your airbox stock. Then you can tape your airbox door open and test it out open and closed and see if it make any difference to you.

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I suggest contacting JD jetting directly with your question. I have a JD Jet kit in my CRF450X and have had a couple of questions over the years. James Dean has always replied personally to my emails and has always been very helpful.

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I have the same bike. I removed the snorkel and cut out the top of the air box, didn't notice much change in noise. I'm running stock exhaust without cutting the baffle. I recommend one size larger on the pilot (should come in the kit but does not). Also did the O ring mod on the accel. pump. My bike runs just great and is quiet, usually blows 94 db at sound test, mostly because of the aluminum skid plate and top cut air box.

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I suggest contacting JD jetting directly with your question. I have a JD Jet kit in my CRF450X and have had a couple of questions over the years. James Dean has always replied personally to my emails and has always been very helpful.

+1 :bonk:

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