The Mercury Mercruiser 8.1L (496 CID) engine family represents robust marine propulsion, encompassing models such as the 496 Mag HO, 496 Mag, 8.1S HO, and 8.1S Horizon. These V8 petrol engines, with a displacement of 8.1 liters or 496 cubic inches, are engineered for reliability and performance, suitable for a range of marine applications. Their design prioritizes power and durability, making them a choice for demanding boating environments. This Service and Repair Manual provides comprehensive guidance for the Mercury Mercruiser 8.1L (496 CID) engines. It covers essential areas including general information, maintenance procedures, troubleshooting, and detailed instructions for engine removal and installation. The manual also delves into specific systems such as starting, ignition, charging, fuel, fuel injection, cooling, exhaust, drives, and power steering. With step-by-step instructions, detailed illustrations, and included diagrams, this manual is an indispensable resource for do-it-yourselfers and experienced mechanics alike, ensuring proper maintenance and repair.