Replacing a float bowl gasket

ScottRNelson

Mr. Dual Sport Rider
I've had a minor fuel drip out of the carburetor float bowl on my XR650L. I'm not sure if it's the float needle not seating perfectly or the rubber gasket on the float bowl being 20 years old and no longer flexible enough to seal properly.

I finally attacked the problem this morning and decided to see if I could remove the rubber gasket and do something to get a better seal. It's hard, doesn't stick up enough to likely seal, and I manage to tear it before getting it out of there anyway. :dunno

So checking with jetsrus.com I see that you can order float bowl gaskets as well as the various jets that you would expect them to carry. I ordered one and should see it sometime in the next week or so.

So the question - do I need to do anything other than thoroughly clean the channel that the gasket goes into and the surface that it is supposed to seal against?
 

matty

Well-known member
Remove old, clean surfaces, replace gasket is all I've ever done. You may want to check your diaphragms while you have the carb off, a crack or a hole can really throw off the tune.
 

ScottRNelson

Mr. Dual Sport Rider
You may want to check your diaphragms while you have the carb off, a crack or a hole can really throw off the tune.
It runs great. I'm not opening up anything I don't have to. It's only been a month or so since I checked the slide and diaphragm anyway.
 

ST Guy

Well-known member
Make a very close, magnified inspection of the float valve for imperfections in the seat and the tip of the needle which is rubber. If any, replace both the valve seat and needle.

FYI, I found all four needles on my ST had cracked and broken rubber needle tips when I inspected them under a microscope. Replaced them all.
 

afm199

Well-known member
Make a very close, magnified inspection of the float valve for imperfections in the seat and the tip of the needle which is rubber. If any, replace both the valve seat and needle.

FYI, I found all four needles on my ST had cracked and broken rubber needle tips when I inspected them under a microscope. Replaced them all.

Yup, those tips get hard, groove, break and crack. I basically replace them if I am doing carb rebuilds.
 

kuksul08

Suh Dude
Float bowl gaskets are usually thick and spongy to account for the pretty coarse carb castings.

I would replace the gasket, float valve (with viton), and clean the jets.
 

ScottRNelson

Mr. Dual Sport Rider
The gasket is getting replaced. The jets don't need cleaning because I put them in there a month or two back and they're fine. I was wondering how it would run with one step leaner on the main jet, found out, and put it back to what I had before because it ran better that way. The float needle is also a new one that I got from the local Honda dealer. I'll do some more checking to make sure the seat is clean.
 

ST Guy

Well-known member
Sounds like you'll be good to go after the float bowl gasket. Though you should check the rubber connection between the head and the carb as well as any orings in that area. Also check hoses.
 
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