Carburettor leaking liquid on top

I own a 2001 Yamaha 4pk 4stroke outboard. When I run it there begins to leak a lot of liquid from the top of the carburettor. I don't know if this is cooling water or fuel. When I take of the plate there is a little maze beneath it, which looks like a cooling canal or something.

Anybody knows if this is normal or if it's fuel?

Thanks,
Kasper.

[boats.net]

That is the float bowl vent, float valve is probably stuck open. The carb needs to be removed and cleaned.

Thanks a lot, I've cleaned the carburettor and it is running perfectly now!