80 KZ750 Float height

I did check one carb at a time, petcock on prime, bike on the centerstand on a level concrete floor. The leak is coming out of the float bowl drain/ overflow, which I understood meant the float level was too low or the needle was not seating fully. I've checked both and can't find the problem, which is why I'm lost.

If it's coming out of the float bowl drain screw area,it might just be a bad/missing o-ring.Or you might even have 2 o-rings in there.An easy check is to just swap out a non-leaker into the leaker and see what happens.ALSO!!!be super careful when working aroung spilt gas.Static electricity could spark a fire.BE CAREFUL!!!

If still leaking and the needles are new then 2 thoughts come to mind.
1. Seats are still dirty. I have had to take a Q tip , dip it in carb cleaner and run it around the inside of the brass needle seat. Once even that was not enough and I used liquid Brasso on the Q tip which really cleaned them up and then carb cleaner on Q tip to remove the Brasso.

2. Check to see if that long brass overflow tube which rises from the bottom of the float bowl is not cracked. It does happen. Take the bowl off, fill with water and see if it leaks. Happened to me and I fixed one tube with JB Weld and then later by soldering a piece of slightly wider tubing slipped over the original .

Good luck

Alright, I finally have this thing figured out. Carb 1 was leaking because a piece of debris got caught under the needle and was holding it slightly open. Cleared that out and made sure there was no more in there. Carb 2 had a cracked overflow tube, so I grabbed another float bowl from the extra set of carbs I got with the bike and no more leak! I don't know why I didn't think to try that earlier, but at least it's fixed now.

Thanks for all the help, now I just have to have my friend help me sync up the carbs and get a new battery and this thing will be ready to ride!

Great !
You're making progress. Running in no time

That's the plan, I want to be riding in the next few weeks.

Glad you found your leak. Just to throw my $0.02 in, I have the same exact bike and had issues with the carbs leaking too. Turns out mine was the small o-rings on the fuel supply line that feeds the carbs. Of Course it was between carbs 2 & 3. I had to split all 4 carbs apart, which was a new experience. It wasn't horrible, but I'd rather not do it again

Fortunately, mine were fine there. The guy I bought it from had them rebuilt, but didn't do a very good job, so I had to fix a few minor mistakes.