31750-ZW9-013 regulator rectifier - Overview. The 31750-ZW9-013 regulator rectifier is a vital part of Honda marine engine systems. It supports the electrical system by converting AC voltage generated by the engine's stator into a stable DC voltage that charges the battery and powers the boat's electrical components. Designed to fit perfectly with existing parts, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Primary function i