Carbs leaking like crazy!

I aquired a '78 kz650b2 on the cheap a couple of months ago. It hadnt run in a few years when I bought it so I did the usual once over. I cleaned and inspected the carbs and rebuilt the petcock. The first time I put gas in it the fuel just ran right out of the drain tubes on the float bowls. I checked all the jets and the float needles when I took the carbs off and they all seemed fine. What is causing this to happen?

Is this happening on all 4 carbs? Assuming the float valves and needles are clean and not damaged, the floats are either upside down or the tabs that contact and lift the float valve needles are not properly adjusted. Another possiblility is that the overflow tube(s) in the carb(s) is cracked. Ed

Are all the drain screws snug?

Could be the old float valves are leaking, just not usual for all of them at once.

Give the whole rack a good smack on the side with your fist. If some of the flows stop/decrease, then its the valves.

GL!