16800-ZY6-003 Water Separator - Overview. The 16800-ZY6-003 Water Separator is a vital fuel system component designed specifically for Honda marine engines. Its primary function is to separate water and contaminants from the fuel, ensuring cleaner fuel reaches the engine for optimal combustion and performance. This component plays a crucial role in maintaining the reliability and durability of your Honda marine engine by preventing water-induced damage and potential operational issues. Engineere