16735-ZW5-003 Fuel Pump Unit - Overview. The 16735-ZW5-003 Fuel Pump Unit is an essential component within the fuel system of Honda marine engine systems. Its primary function is to draw fuel from the tank and deliver it under the correct pressure to the engine's fuel injection system, ensuring optimal combustion and engine efficiency. Designed specifically for Honda EFI outboards across the BF175A, BF200A, BF225A, and BF250A series, this fuel pump unit guarantees seamless integration with exist