This workshop manual covers Yanmar GM and HM series diesel engines, designed for industrial applications. Yanmar Co., Ltd. is renowned for its engineering quality and reliable machinery. These engines are built to perform in demanding environments, and this manual provides comprehensive information to ensure their optimal operation and longevity. This English-language workshop manual is intended for the repair and maintenance of specific models within the Yanmar GM and HM series. It details essential procedures, including scheduled maintenance, engine overhaul, and troubleshooting guidance for common issues. The manual also includes technical specifications, diagrams, parts identification, safety precautions, and precise torque values, making it an indispensable resource for owners, mechanics, and technicians.