This service repair manual covers Volvo Penta marine engines, specifically the MD2010, MD2020, MD2030, and MD2040 models across their A, B, and C variants. These diesel engines are engineered for reliability and performance in marine applications, featuring robust circulation pump, sea water pump, and oil pump systems. Their design emphasizes durability and efficient operation, making them a trusted choice for various maritime needs. This comprehensive manual provides essential information for maintaining and repairing your Volvo Penta marine engine. It includes detailed technical data, step-by-step repair instructions, and clear illustrations and diagrams. Key areas covered encompass engine components such as the cylinder head, valves, and crank mechanism, as well as the fuel system, including the injection pump and injectors, and the electrical system with alternator and starter motor. Maintenance procedures for oil filters and cooling systems, alongside troubleshooting guidance, are also thoroughly detailed to ensure optimal engine performance and longevity.