Sick of the leak

I have a 1980 kz1000 shaft... I am new to carburetted motorcycles. I noticed a leak about a week ago, I pulled the carburetor off and cleaned it all out. At first I thought this fixed the problem. I was wrong. While riding today I noticed that the bike would begin to leak fuel while stopped at an idle. The fuel if dumping out of the second carb. I was guessing the float was sticking open. When I pulled it apart again and checked the float it seemed to be functioning properly.. What else could be causing this leak and what can I do to fix. I've got a gorgeous weekend in the 80s ahead of me and I would love to ride. (without stopping all the time to fill up.)

Pull that float bowl off again and have a look at the brass tube that stands straight up in the bowl. I had one carb with a steady leak even when the fuel level was right. I discovered that the brass tube in question had a very fine longitudinal crack that caused the leak.

tap on bottem of bowl and see if it stops.
dump a big can of sea foam in the tank and take it out on the highway and blow it out

the float valve (needle and seat) is leaking, replace it

You can also polish the needle tip and the inside of the brass seat. I do it as normal maintenance every six months to prevent leaks. Put the needle in a hand drill and use some 600 sandpaper laid over a popsicle stick to polish the angled tip of the needle until it is dead smooth. If the needle/seat can not be smoothed with a light polishing, replace them

I use a Q tip and chrome polish to smooth the inside of the brass seat. Wrap a bit of tape around the threads of the brass seat and gently install it into thehand drill and spin it using the Q tip to go inside with the polish.

NOTE: If not already done, you need to rinse out your gas tank, clean the petcock assembly, and install inline fuel filters. If not, reapairing carburetors will be a lifetime hobby as dirt and sediment work their way downhill into the carbs.

testarossa wrote:

Pull that float bowl off again and have a look at the brass tube that stands straight up in the bowl. I had one carb with a steady leak even when the fuel level was right. I discovered that the brass tube in question had a very fine longitudinal crack that caused the leak.

I've also had this happen a few times....drives you nuts until you find it.

Thank you everybody for your help, turns out it was the float needle. While replacing that I also took a little more advice and installed a fuel filter since I found some trash in the carb. Thank you again everybody. I'm off to ride!