2007 wr450 jetting question.

6 replies to this topic
  • yoshdrz400

Posted June 09, 2008 - 02:19 PM


well i've jumped from the drz forum to the WR forum and all i can say is why did i wait so long! But now heres the question for you guys i bought a 2007 wr450 and i also bought fmf pipe with power bomb header, if i install this with a jd jet kit will that eliminate that off idle bog or is there more? Also does the AIS kit make that much of a difference? most of my riding is done from 0 to 5000 ft. any imput would be awesome thanks guys.

  • tribalbc

Posted June 09, 2008 - 02:47 PM


Good to see another BC WR :thumbsup:

Dump the AIS. Not an issue here in BC anyways. Will never be able to get rid of the decel pop or jet it right otherwise. I personally feel it gives a bit of a preformance gain by cleaning the jetting up.
Install the jet kit ( have fun, the carbs a bitch ) and pipe and see how she goes. It should be close to right.
If you still have a bog when you wick the throttle you might want to look into the AP mod.

I have an 07 WR with a 08 YZ pipe, ride about the same altitude as you. The jetting that works for me is a 48 pilot, GYTR needle 4th clip and a 170 main.

  • William1

Posted June 09, 2008 - 04:24 PM


Two things.
Do the ORing mod
Get a smaller leak jet (55 or smaller - some go to a #40, depending on the type of riding you do mostly) or an adjustable one.

Jet kit will improve general running but has little effect on the bog. I know the James Dean kit comes with a smaller one (#70, I think), but it is not small enough for most

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  • Demo_Slug

Posted June 09, 2008 - 07:12 PM


the JD kit does come with two orings. a thick one and a thin one. I used the thin one.

:thumbsup: get a fuel screw. install the jd kit, use the recomended setting. tweek the fuel screw until you get crisp throtle. bike will run good.

  • yoshdrz400

Posted June 09, 2008 - 07:38 PM


cool i will try those ideas. i should have the jet kit tomorrow so i will install asap. where abouts in bc are you if your in the south west maybe you can come show me how to ride this beast properly.

  • tribalbc

Posted June 09, 2008 - 08:09 PM


Yeah I'm in the SW. Pemberton just N of Whistler. And you ?

  • beezer

Posted June 10, 2008 - 07:37 AM


Messing around with leak jets on an aluminum WR450 sucks. I'd get a Merge adjustable leak jet.

The stock accelerator pump is lean and you have to use a richer pilot jet to cover for it so the bike isn't really crisp.

I use a 42 p-jet on my 08.


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