This manual covers the Yanmar SD20, SD30, and SD31 Sail Drive Units. These units represent robust engineering designed for reliable marine propulsion. Their innovative sail drive design, combining inboard and outboard functionalities, offers efficient power delivery and a clean transom profile, making them a preferred choice for a wide range of sailing vessels.

This comprehensive repair service manual provides essential information for the maintenance and repair of your Yanmar Sail Drive Unit. It details procedures for the forward, neutral, and reverse gears, along with technical specifications for propeller types, cooling systems, and lubrication. The manual also includes guidance on anode replacement and drive shaft seal maintenance, empowering owners and technicians to ensure optimal performance and longevity of the unit.