This comprehensive manual covers Mercury Outboard Motors manufactured between 1965 and 1989, encompassing a range of 2-stroke, water-cooled engines from 45HP to 115HP. It details specific models including the 45HP, 50HP, 500, 60HP, 650, 65HP, 700, 70HP, 75HP, 80HP, 800, 85HP, 850, 90HP, 100HP, and 115HP. These robust engines, designed for various marine applications, feature carbureted fuel systems and can utilize pre-mix oil/fuel or oil injection lubrication, paired with an outboard drive system offering forward, neutral, and reverse gears, and supporting remote or tiller steering controls. This English-language manual serves as an essential resource for owners, technicians, and mechanics, providing detailed information on routine maintenance, advanced troubleshooting, and repair procedures, including engine removal and installation. It also includes vital technical specifications, electrical system details, intake and exhaust system information, body work, and shock system coverage, alongside a complete parts catalog for accurate component identification and replacement. The manual is designed to facilitate the efficient upkeep and repair of your Mercury outboard motor, ensuring optimal performance and longevity.