03 WR450 keihin 5TJ1 float seat issues HELP

So this is what I have. I picked up a 03 WR450 last week and shouldn't have. To start off with the fuel won't quit flowing out the overflow. I pulled the carb and cleaned it out and it didn't seam to awful bad. The float needle looked good so I figured that there was just some debris in it. Well after the third time back on the bike I narrowed it down to the float seat's "O" ring is bad (if it has one, some say it does). The problem is the seat doesn't come out. I've done some research and some say you can force it out. But I haven't ben able to do that either. I called Keihin and talked to them and they say its not a serviceable part and to by a new carburetor, YUK. But there are to many smart guys out there that I am certain have had the same problem. I thought maybe I could get it out and if it doesn't have a "O" ring I could epoxy it back in. But I don't know if that would work either. So here I am looking for some HELP.

If nothing else what other carburetor might I be able to use?



A slidehammer did not work?

You can see that it is pressed in.

You can also see that the seat is pitted, so perhaps all you need to do is grind the seat to re create a good mating surface for the needle.........

Edited by TheKoolAidMadeMeSick

Make sure the pin on the back of the needle isn't jammed. Often the tiny spring inside gets stuck. The pin should spring in and out freely. It's what maintains the even pressure.


I haven't figured out how to attach the slide hammer. Do you have a good ideal on how to attach a slidhammer to the pressed in seat?I did run a M7-0.75 tap up into it trying to get a grip on it with a pair of locking pliers. I heated it up with a heat gun to the point you couldn't touch the body. Still no luck of pulling it out.. I plan on trying to find a M7-0.75 bolt to run up into it that ill be able to attach the slide hammer to.


I did inspect the spring in the plunger and it is moving freely.

Once I get past this challenge it will be off to the next one on the list. The Starter!

Thanks for the help guys and keep the ideals coming. I won't be able to work on it for the next two weeks due to work. But after that I plan on getting right back on it.

Were you able to source the replacement seat?


Threading it is a great idea


You have support the  carb body in such a way that it is at rest on wood, with a gap below to access the offending part

You cannot clamp the body, or pinch the body to hold it.

Most slide hammers alrady have a threaded end, but it probably won't be metric

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