Keihin CV Carb overflow

I'm working on getting the KZ750N going again, and we hooked it up to fuel today and fuel started dumping out the bottom drain on the carbs. I can't recall if these carbs have a seperate overflow circuit, or if they're the type that use the combo drain/overflow.

Just trying to track down this problem so I can get her back running again. I've got spark and she's cranking over good now, almost there.

I'm pretty sure you have the same carbs as on my 1980 750 /4 so the overflows are the combo drain / overflow type.
Only a few reasons gas may be flowing out
Drain screws not closed ( unlikely)
Float needle valves dirty or worn
Brass overflow tubes cracked

Good luck