i have a couple of those 6 gal metal gas tanks (removable/topside) with johnson fittings and fuel guages on top. one of them leaks out fuel when it is filled past a certain point. it seems as if that little ball valve is stuck or broken. anyone know where to get the replacement part or how to take it apart? i took it off the top of the tank, and couldnt see any way to get to the valve. looked all over on ebay and i cant buy just the fitting part on there. any help would be appreciated.