kz750m overflowing carburetor

I bought a kz750m a few years ago off of craigslist as a project bike and like many projects, it got put on the back burner. I was able to get it running but it was backfiring and pouring (no exaggeration) gas out of the carbs. I tore them apart and cleaned them out. They were pretty dirty but look pretty good now (checked the floats and they both seem to be good). I kept both carbs together so everything would stay in sync. I have two ideas on how to fix this but haven't had time to try it.

First: I've heard that there is a float adjustment tab that can be bent if the floats aren't working properly. This seems to make sense but I have never had to adjust floats and if you really think about the inner-workings of the needle and float attachment, it doesn't make sense on why you would have to change that tab displacement. This leads me to my second option.

Second: I need new needles. I would love to try this option but I don't know of a good place to buy them. Any suggestions would be greatly appreciated. I really can't seem to find parts for this bike except on ebay.

Assuming the float needles and orifices are clean, are you positive you did not install the floats upside down? It has been known to happen. Ed

Z1Enterprises.com have float needles and seats for the 750 twins.
If the floats are installed correctly then I wouldn't mess with the tang to change the float height just yet. Changing the float height changes the fuel level in the bowls and the level can effect whether the motor runs rich or lean

The seats can be cleaned with a bit of carb cleaner on a Q tip but if the needles or seats are worn then they will need to be replaced. This is a cheap fix and Z1 Enterprises are quick to ship.