This manual covers Mercury/Mariner Outboard Motors manufactured between 1965 and 1991. These 2-stroke outboard engines range in horsepower from 2.2 HP to 40 HP, encompassing numerous models such as 2.2, 3, 3.5, 3.6, 3.9, 4, 4.5, 5, 6, 7.5, 8, 9.8, 9.9, 15, 18, 20, 25, 35, and 40 HP. Designed for reliable marine propulsion, these outboards are known for their robust construction and straightforward operation, making them a popular choice for a variety of watercraft. This comprehensive Service Repair Manual provides detailed guidance for the repair, service, restoration, maintenance, rebuilding, and diagnosis of your Mercury/Mariner Outboard Motor. It includes clear, step-by-step illustrations, exploded views, engine component breakdowns, and part numbers to facilitate accurate work. The manual also covers essential topics such as preventative maintenance, starter operation, tiller handle operation, throttle shift linkage, and troubleshooting common issues like starting problems, rough idling, and excessive smoke. Wiring diagrams are included to aid in electrical system diagnostics.