Need Help With Jetting.

3 replies to this topic
  • grizz_7

Posted April 09, 2006 - 11:03 AM


I have a 04' WR450. I would like to get it jetted so very minimal changes will need to be made throughout the summer. I will be riding at an elevation right around 1000' and in temps ranging from 65 to 90 degrees.

Mods that have ben done already include: throttle stop cut down, airbox snorkel removed and side holes cut out, grey wire disconnected and a pmb insert in the exhaust.

Right now i have a 170 main, 48 pilot, 40 leak, and 72 starter. The air screw is 1 3/4 turns out. The needle is the stock 04' with the clip in the fourth slot. I dont want to spend another $70 on the JD kit since i read the stock 04' needle is pretty good.

The bike ran like a raped ape but with a bad low end bog with this setup without the pmb insert. But now after the insert it runs like crap and i am looking for a new starting point for jetting.

I looked through many many threads and finally decided to make one of my own with my specific setup. Thanks for sticking with me and any input you have would be greatly appreciated. Im a jetting noob. :thumbsup:

  • beakr

Posted April 09, 2006 - 03:59 PM


My '04 runs good year round :thumbsup: from 2800' to 6000' with 48 pilot, 168 main (may drop back to 165 in summer), stock leak, stock starter (although starting is hard when down around 40F) stock '04 needle clip #4. Only mods are throttle stop, snorkel removed, holes punched out on right side of airbox, GYTR insert in stock muffler. I tweak the fuel screw to correct the occasional stumble when elevation or temp changes too much(MSR, but same as Zipty) but my bike doesn't really bog at all. What throttle position (not rpm) is it bogging at? You may be getting too much fuel--have you tried going back to stock leak jet and/or dropping your main?

Indy is the jetting guru :confused: on this forum--if he chimes in, I'm sure he'll set you straight. . .Indy???? :thumbsup:

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  • dl19

Posted April 09, 2006 - 07:56 PM


Drop your main to a 168 or a 165. I would guess you might be a little rich regardless of temp. and very rich for the colder temps.

  • grizz_7

Posted April 09, 2006 - 10:20 PM


Thanks for your input guys. I will hopefully get some time to play with it tomorrow. I will let you know how it goes.


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