This service repair manual covers the Mercury Mercruiser 502 CID engine, produced between 1993 and 1997. This V8 engine, with a displacement of 502 cubic inches (8.2 L), offers a typical horsepower range of 300-425 hp, depending on the specific application and tune. It features a robust design, available with either carbureted or fuel-injected fuel systems and either raw water or freshwater cooling. The engine is compatible with sterndrive or inboard drive types and weighs approximately 700-800 lbs for the long block. This engine is engineered for reliability and performance in demanding marine environments. This manual provides comprehensive guidance for maintaining and repairing your Mercury Mercruiser 502 CID engine. It details essential procedures, including lubrication recommendations, oil and filter types, and typical service intervals for oil changes and spark plug replacements. Technical specifications, troubleshooting information, and safety guidelines are also included to ensure proper operation and longevity of the engine. This resource is designed to assist owners, mechanics, and technicians in effectively servicing the engine, ensuring it operates at peak performance.