41112-ZW1-B03 Vertical Shaft - Overview. The 41112-ZW1-B03 Vertical Shaft is an essential component within Honda marine engine systems, specifically designed for the water pump and power transmission system of marine outboards. This Vertical Shaft serves as the primary rotating shaft that transfers power vertically from the engine, playing a vital role in ensuring reliable propulsion and efficient operation of your marine engine. Its design ensures seamless integration with existing parts, maint