Carbs won't stop leaking gas

I have a 1980 KZ750 . I live in Chicago and It got hit by a car while parked last year and has been leaking gas from the carbs ever since. It's so bad I can't even
Keep gas in it.

I pulled the carbs off, took them all apart and cleaned everything. While I did that I found a float needle that didn't have any spring to it anymore so I replaced that and also a gasket on the float bowl needed and got replaced.

I put all new fuel lines and waste lines on it when I put it back together. I put gas in it and everything was good. I rode 3 miles everything fine. I filled the tank on my way home and when I got about 200 yards from my house I noticed it was running like crap and pissing gas again. I parked it and drained the full tank. Needless to say I'm stressed about it.

It's like gas won't stop flowing when it's off and won't stop over flowing while it's running. Any ideas?

I took the carbs off again and am sort of stuck. Any ideas are appreciated! Thanks guys.

Rebuild the petcock.
Check the fuel level in each carb using the clear tube method.
Install a new fuel filter.
You may need to flush the tank as the accident may have knocke,d loose some debris.

What TexasKZ said...

And, install a muffler on that thing.

First you have to determine from where the leak is coming from. Often the interconnecting fuel pipes, between the carbs, O-rings are the culprit. They look to be BS-34 carbs so getting them apart and changing the O-rings is easy enough.

Thank you guys for the suggestions. I think you might be on to something with the petcock rebuild.

I'm also going to try to post a video of what I found that just seems to be a little weird. Maybe you guys can tell me if its worth looking into.

Is gasoline constantly flowing from each and every overflow nipple (hose)?

Good Fortune!

This time it seemed to only be coming out of carb #3. Overflowing non stop to the point of dripping out of the air filter.

In the video, the weird carb has a bad or broken or crapped up spring in the needle valve. If that is the case, a new one is needed.
Otherwise, the float could be bottoming out on the carb body, meaning something is bent, or that is the wrong float.

Kz I thought the same thing. For trial and error I took the float and needle out of # 4 and put it in #3. It did the same thing. So maybe something is really jacked up?

WhitK1980kz750 wrote: This time it seemed to only be coming out of carb #3. Overflowing non stop to the point of dripping out of the air filter.

Crankcase oil could have become diluted with gasoline. If so, would take whatever means necessary to prevent further gasoline from entering the carbs; then change the oil and filter; and don't allow gasoline into the carbs until the overflow issue is resolved.

In #3 carb, would check for any imperfection or grit or crud in the orifice in the float valve seat which might be disallowing complete seal when the pointed tip of the float needle presses into the orifice. Can use a q-tip chucked into a drill to clean the orifice. Use a little carb cleaner on the q-tip, and perhaps a little Brasso if necessary.

Would also suspect that the overflow circuit in carb #3 is malfunctioning (likely obstructed), because gasoline is rising high enough to enter the carb bore, which means that gasoline has risen higher than the the top of the overflow tube (excess gasoline is failing to escape through the overflow circuit).

It's important to have both a functional float valve and a functional overflow circuit.

Good Fortune!

Looking at your video again this morning. I notice that the level adjustment tang on the #3 carb seems to be adjusted higher than 4. So in effect the float never really hits the needle forcing it closed. Try bending the tang down, in this view, to lower the fuel level. ONLY if the springy part of the needle is free moving and has spring pressure behind it,

I have often used my HF heat gun and PB Blaster to free up the spring top on those needles. It may take a few times but soak in PB for a few minutes then holding the needle in a pair of pliers heat up the top of the needle. I've had them so hot you can burn yourself easily so be careful. Then tap the spring part on the work bench. Repeat until the spring works like normal. Let it cool and see if it's still springy. If not repeat. Once free it will stay that way for years as far as I can tell.

WhitK1980kz750 wrote: Kz I thought the same thing. For trial and error I took the float and needle out of # 4 and put it in #3. It did the same thing. So maybe something is really jacked up?

That does suggest that the problem is in the carb body. If so, it seems that either something is preventing the float from moving through its full range, or the seat is too far down for the needle to reach. If you remove float and needle from both of those carbs you can make a careful comparison. You can also insure proper functioning of the needle plungers.

Whatever the problem in the carbs, the petcock also needs attention, as it is supposed to prevent fuel flow when the engine is off.