This manual covers the YANMAR 1GM, 2GM, 3GM, and 3HM Series marine diesel engines, designed for reliable marine propulsion. These inboard diesel engines are engineered for demanding maritime applications, offering robust performance and durability. Their construction emphasizes efficiency and longevity, making them a trusted choice for boat owners and operators requiring dependable power on the water. This comprehensive workshop and service repair manual provides detailed guidance for all repairs and servicing of your YANMAR marine diesel engine. It includes essential technical specifications, maintenance procedures, and troubleshooting information to ensure optimal performance and longevity. This resource is invaluable for owners, mechanics, and technicians seeking to maintain and repair these engines effectively.