Mercury - Fuel Filter TwoStroke DFI Jet Drive Series Marine-Grade Filtration 884743. Overview. Every boater knows that the engine's mood sets the tone for the entire day on the water. When the motor runs clean and steady, everything else just feels easier - the throttle responds the way you expect, the ride smooths out, and you settle into that rhythm only a good-running boat can give you. The Mercury Marine part number 884743 Fuel Filter plays a small but crucial role in keeping that feeling al