hey i have a 400fis. the needle in the carb keeps coming out of its little hole/shaft thing, and obviously runs like crap. I fix it, but after riding it somehow comes out of the hole AGAIN!!! I fix it, runs fine, then it starts barley running(or not at all), i go look and sure enough the needle is out ot the hole again!

Im kinda stumped.

 

I am assuming this means the neede valve is being found inthe bottom of the float bowl?

If so there should be a little plastic clip on the float bowl that is broke off that hangle onto the needle valve for you and keeps it from moving.

If the needle you reffering to in the one onthe throttle cable then there is a spring and a c-cli[p that holds that one in place.

Try looking at a blown up image of a parts diagram of your carb and make sure all the parts,clips,springs are there them look at the parts more closely to make sure they are not worn or damaged.

SJ

 

I think we are talking about the same thing, swampy.
If you look through the carb its the needle thing the goes vertically from top to bottom throught the middle of the carb. I look at a diagram and it said "jet needle." Its on the float thing and lifts up, but i GUESS when it tries to go back down it misses the hole and hits the side of the wall in the tunnel that runs through the carb.

In a nutshell, the needle doesnt go back down in the hole, (misses) and gets jammed i think.

Sorry for lack of terminology and actual names of the parts within the carb....

 

OK, "Jet needle" gets stuck of jammed. After looking at a parts diagrammyself I amwondering if the needle you have is bent? OR maybe has gunk built up where it rides causing it to stick?

Other thing that comes to mind is a vacuum leak there under that cover.

SJ