This manual covers Yanmar Inboards, marine inboard diesel engines designed for boat propulsion, produced between 1975 and 1998. These engines are recognized for their robust engineering and reliability in demanding marine environments. While specific performance metrics like horsepower, torque, and displacement vary across the range of models, all are built to deliver dependable power for a variety of vessels. The purpose of this Service & Repair Manual is to provide comprehensive guidance for the maintenance and repair of your Yanmar inboard engine. It details essential procedures, technical specifications, and safety protocols necessary for optimal engine performance and longevity. Whether you are performing routine maintenance, troubleshooting an issue, or undertaking major repairs, this manual serves as an indispensable resource for owners and technicians alike, ensuring your engine operates efficiently and safely in its intended marine application.