- Dirt bike & ATV parts

Loose jet needle

Nov 3, 2013
I just blew a piston and had to take apart the top and bottom end to get all the broken pieces out... Everything went smooth until Im putting the carb back in and drop the throttle valve. The jet needle is loose but I can't remember if that's how it was. I'm dumping gas everywhere now out the overflow. Could it be from the loose jet needle for is it from the floats... Or both
Apr 18, 2006
You didn't mention what bike you have.

What do you mean by "loose"?

On my carbs the needle just slides into the throttle slide and is held in place by the clip that fastens the throttle cable. There is a small circlip that can be moved to different slots on the needle to adjust exactly how far down the needle goes, and thus the mixture.

With the throttle cable attached I would expect that you should be able to rotate the needle but there should be no play up/down.

If you dropped it I would be concerned that it got bent, which would case a lot of problems.

As for gas flowing out, that would be from a stuck float, and would have nothing to do with the needle.

- a d v e r t i s e m e n t -

High Lord Gomer

Poked with Sticks
Sep 26, 1999
I had a needle in an 83 RM250 that was supposed to also have a spring on top of it that held it in position. It was compressed / worn such that the needle bounced around and even hung the carb wide open sometimes during those rare occasions when I actually twisted the throttle all the way. If it is truly loose, figure out what needs to happen to tighten it.