I have just completed a Clark Craft TU 14. This is an all wood 14 ft. tunnel hull boat. I installed a 50 H.P. Johnson outboard with electric trim. My problem is at medium throttle I have water coming over the transom. It seems that the water coming thru the tunnel at low speeds hits the motor shaft housing and shoots straight up, hitting the motor mount and gushing over the transom. Is this common with tunnel hulls and what is the cure ?