If fuel leaked from a fuel tank on your boat, would it find its way to the "well" under the engine? If so, were the tanks full of fuel, or nearly so, when the boat was lifted? I'm asking because it's possible that when your boat was removed from the water, it was transported and/or blocked up in an attitude that doesn't occur when it's afloat. For instance, the bow might have been, or is currently, lower than it would be afloat. In that case, the fuel may have leaked from fittings on top of the tank that are not as tight as they should be. Please don't ask how I know this.
Other than that, it's got to be a tank, fitting, line, filter, or pump leaking fuel. It needs to be treated as a serious problem.