This repair manual covers the Yanmar 1GM(10L), 2GM(F)(L), and 3GM(D)(F)(L) marine engines, designed for reliable marine propulsion. These internal combustion engines are built with robust engineering principles, ensuring dependable performance for a variety of maritime applications. The Yanmar line is recognized for its quality and efficiency, making these engines a trusted choice for boat owners and operators. This comprehensive repair manual provides detailed instructions for servicing and maintaining your Yanmar marine engine. It includes essential information on routine maintenance, engine removal and installation, fuel, lubrication, cooling, intake, exhaust, and electrical systems. Furthermore, the manual offers advanced troubleshooting guidance and parts lookup capabilities, empowering owners, mechanics, and technicians to effectively diagnose, repair, and preserve the optimal functionality of these engines.