16805-ZW5-003 Water Separator Cup - Overview. The 16805-ZW5-003 Water Separator Cup is a high-quality component designed for Honda marine engine systems. This essential part plays a critical role in filtering water and debris from the fuel system, ensuring that only clean fuel reaches the engine. By effectively removing contaminants, it helps maintain reliable and optimal engine performance, prevents damage to fuel system components, and supports the overall longevity of your marine engine. Engi