This Service Repair Workshop Manual covers Mercury Mercruiser 496CID/8.1L Gasoline Engines. These powerful engines are designed for marine applications, offering robust performance and reliability. The manual details various sterndrive and inboard models, including the 496 Mag HO, 496 Mag, 8.1S HO, and 8.1S Horizon. With a displacement of 496 cubic inches or 8.1 liters, these engines feature electronic fuel injection and are engineered to meet demanding operational requirements. This comprehensive manual provides essential information for maintaining and repairing your Mercury Mercruiser 496CID/8.1L engine. It includes detailed procedures for engine systems such as ignition, charging, exhaust, cooling, and starting, along with power steering pump information. The manual also covers transmission details for compatible Velvet Drive and Hurth transmissions, and offers guidance on troubleshooting and maintenance schedules. This resource is designed to assist owners, mechanics, and technicians in ensuring optimal performance and longevity of their engines.