I have a 115hp mercury(1995).I let set up for a year.I was surprised when I took it out of the barn that it started.the only problem is it is pumping gas out of every carbuator.there are two holes at the top of all four of them.one hole has a brass screw in it and the other I assume is an overflow hole.If all the floats were stuck open as I have thought of would it start and run? Does anyone know what has happened and what to do to fix this?