idle adjustment 2004 wr450f


I got a used 2004 WR450f that had all the uncorked mods with a GYTR Exhaust tip, had been rejetted.

The bike idles in neutral sounds like it is constantly got Hot Start on. But I checked that and when I adjust the screw thingy out it idles even higher. So it's not the hot start being on..

My next thing was the idle screw.. but wasn't sure how to adjust. I took a pic below. The black knob (circle A) won't turn at all, and when I turn that screw (circle B..) it doesn't seem to change the idling at all.


The screw on circle B has 1-4 or 5 printed on it.. and when I look at it currently sits between 1 and 2...

Did the previous owner just rejet it to be like that? Is that normal? I'd like to not have to rejet as the bike runs fine other then it idling seemingly high ... When I pull clutch in , the idle feels alot lower and much lower sounding.

Here's a video of bike idling (no hot start- 'normal' idle)

Any help would be much appreciated.

Edited by whatsitmatter

Gently turn the fuel screw all the way in (red anodized screw).

Back it out to 1 turn out

Start bike

Adjust idle with black idle screw (it will turn, it's just tight) to get the lowest idle possible

Now adjust the fuel screw for highest idle.

If it goes to high, drop it again with the idle screw and repeat.

"It's been re-jetted" tells us next to nothing.

If the idle screw is truly to tight to turn, you need to remove the throttle wheel cover, and clean off and lube the threads for the throttle stop.

If you find lots of crud in there, you should probably remove the carb and clean it with spray brake cleaner, after removing the pilot, main, and air jets.

Now you can catalog the actual jets in there too.

Thanks. The red anodized screw, fuel screw, is screwed all the way in and back out one turn roughly.. maybe 1.5.. That's the way the bike sounds in that video like that.

As for the black knob- idle- it won't turn.. I mean I can turn it maybe an 1/8 twist but it goes right back to original position. If I force it any more it'd probably snap off so I don't know what's going on there. I'll take a look at it again tomorrow.

And I mentioned the bike was rejetted because I'm not too sure if that can affect idling as well.

Edited by whatsitmatter

Sounds like the idle speed adjuster Is seized.

As suggested, you will need to remove the throttle wheel cover and clean and lube threads.

At the end of the day, you may as well pull the carb out, strip it down, clean and check everything. Benefits are you know what jets are current, the condition of everything and more importantly, gain an understanding of how everything works. It is likely anyway once you correct the seized idle adjuster, the next tune issue will raise its head and you will be into An unknown carb once again.

My 2 c. Good luck with it

Yeah I may as well open the Carb while I'm in that area and clean it up if need be. The bike runs great other then the high idle rpms...

Must be the idle screw seized / got jammed in wrong position -

Thanks for the input.

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