This service repair manual covers Mercury MerCruiser marine engines, specifically models utilizing GM V-8 engines with displacements of 305 cubic inches (5.0L) and 350 cubic inches (5.7L). These gasoline-powered engines are designed for marine propulsion, embodying the engineering quality and reliability associated with Mercury MerCruiser products. This manual provides comprehensive information to ensure optimal performance and longevity of your marine propulsion system. The purpose of this manual is to provide detailed guidance for the maintenance, repair, and troubleshooting of your Mercury MerCruiser marine engine. It includes essential technical specifications, safety guidelines, and step-by-step procedures for various maintenance tasks. Owners, mechanics, and technicians will find this English-language resource invaluable for understanding and servicing the engine, ensuring its continued reliable operation on the water.