04304-ZW9-020 Neutral Switch Set - Overview. The 04304-ZW9-020 Neutral Switch Set is a crucial component in Honda marine engine systems that supports the starting and safety system. Its primary function is to ensure the engine will only start when the transmission is in the neutral position, preventing accidental starts in gear and enhancing operator safety. This neutral switch set is designed to fit precisely with Honda's marine engine systems, ensuring seamless integration with existing parts,