Owning a Mercury Mercruiser 496 CID / 8.1L engine means commanding serious power on the water. To keep your vessel performing at its peak, you need the right technical guidance—this Service Manual is your definitive resource for maintenance, troubleshooting, and repairs, ensuring every outing is smooth and reliable. Designed for mechanics, marine technicians, and knowledgeable boat owners, this manual provides step-by-step instructions for the 30 Series engines, covering both Sterndrive (MCM) and Inboard (MIE) configurations. Whether you're servicing the 496 Mag HO or the 8.1S Horizon, this guide delivers factory-accurate procedures. Comprehensive Coverage: From the Electronic Fuel Injection (EFI) system to the Distributed Electronic Ignition, every critical component is detailed. Step-by-Step Repairs: Includes removal, installation, and adjustment procedures for the Velvet Drive 5000 Series and Hurth Transmission. Diagnostic Support: Troubleshooting guides for electrical, fuel, cooling, and exhaust systems to minimize downtime. Factory Specifications: Torque values, fluid capacities, and alignment procedures to ensure precision work. Available as an instant PDF download, this manual puts professional-grade knowledge at your fingertips. Avoid costly dealership visits—equip yourself with the same reference used by certified Mercruiser technicians. Invest in peak performance. Whether you're maintaining, repairing, or upgrading, this manual is your essential partner for keeping your Mercury Mercruiser 8.1L running flawlessly.