Leaking Gas Out of Airbox overnight

Hello everyone,

I've been fighting this problem for a while and I am stuck and can't figure out what else to do. I have an 82 750 twin, and it runs great finally. The only problem I am still having with it is after it sits overnight there is a puddle of gas in the airbox and when I stand the bike up it drips a bunch more out. I have rebuilt the petcock so it doesn't leak anymore, I have reset the floats so they are correct via the tube test, but the problem still persists. Do I need to get a rebuild kit for my carbs or is there something that I am missing?

Thanks
John Jones

Is it on centre- or side stand?

Check the brass tubes, overflow tubes, in the float bowls. They crack. Otherwise, possibly the O-Ring where the float needle/ seat assy installs in the carb body. Or just some dirt on the float needle/ seat assy. Have you cleaned the Tank? If not you can get crap coming through still.

Motor Head wrote: Check the brass tubes, overflow tubes, in the float bowls. They crack.

I had this problem, one of the over flow tubes had a split running length wise, very hard to see if your not looking for it.
Swamped it out with a spare bowl.

JD

Check the carb bowls for debris and clean/check the float needles & seats. Some guys buff the seats w a q-tip & polish. I used brass wool wrapped around a q-tip. Whether or not there's debris, go ahead and drain & clean the tank - inspect the fuel for debris & rust. Install new fuel line & a fuel filter. Also, double check the petcock's functionality to make sure it isn't leaking - easy to do.

Checked the brass tubes, sure enough, one of them is cracked, but it's way down by the bottom, the rest of it is fine. Would a crack all the way at the bottom cause the issue?

my mistake - not sure where the leak is.

so now the question is, what is that brass tube for and how do I fix it? it doesn't appear to come out of where it is in the carb.

Just to make sure we are talking about the same brass tube, it's the long one that extends into the carb bowl right?

johnjones750csr wrote: so now the question is, what is that brass tube for and how do I fix it? it doesn't appear to come out of where it is in the carb.

Just to make sure we are talking about the same brass tube, it's the long one that extends into the carb bowl right?

It's the overflow tube. When gasoline rises high enough to reach the top of the tube, the gasoline begins flowing into the top of the tube, and runs down through the tube, exiting through the nipples on the underside of the float bowl, and usually on through rubber overflow hoses (attached to the nipples), routed to discharge onto the ground underneath the bike.

Good Fortune!

Several repair techniques, including:
Solder;
JBWeld;
Plastic hose snugly fitted over the cracked tube;
Slightly larger tube fitted and soldered into position over cracked tube;
Heat-shrink tubing fitted over the cracked tube.

Good Fortune!

Try posting in the want ads, maybe someone has a spare bowl.

ok, I think we are talking about a different tube here. The overflow on my carbs (the second T fitting) is not hooked up to anything. The fuel is not coming out of there. the fuel is draining out of the bottom of the airbox and the only thing that is hooked to the air box is the airflow tubes that hook to the carbs. There is no overflow running into my airbox and the fuel is not coming out of there. there is nothing wrong with the float bowl at all. the tube that is cracked is the little tiny brass one that slides into the float bowl when you put it on.