This manual covers YANMAR YDG Series Industrial Engines, specifically designed for Diesel Powered Generators. The YDG Series represents robust engineering, offering reliable performance for demanding industrial applications. This service repair manual provides comprehensive information for models YDG2700EV-6EH, YDG3700EV-6EI, and YDG5500EV-6EI, ensuring users can maintain and operate these powerful engines effectively. The purpose of this English-language, 286-page service repair manual is to guide owners and technicians through all aspects of maintenance and repair. It details service and repair procedures, including assembling and disassembling components, troubleshooting common issues, and understanding complex wiring diagrams. With detailed illustrations, including electrical and hydraulic diagrams, schemes, and exploded views, this searchable and printable manual empowers users to perform their own repairs, saving time and money.