I have an Evinrude outboard with a Briggs and Stratton power head that has exhaust tubing that runs from the engine to below the water line (when mounted on the boat). I have not water tested the motor with this exhaust system. I have read conflicting information online regarding needing a relief hole drilled in the pipe above the water line. Some say you don't need to drill one and others say if you don't, you can suck water up into the engine. I want to get a straight answer before I water test the motor with it's underwater exhaust. Thanks