This repair manual covers Mercury 45-220 HP outboard motors manufactured between 1977 and 1989. These marine outboard motors are engineered for reliable marine propulsion, offering a range of horsepower options suitable for various watercraft. The motors feature robust construction, utilizing water-cooled systems, advanced ignition technologies such as CDI, and efficient fuel delivery through carburetion or fuel injection. Many models are equipped with electric start and power trim and tilt systems for enhanced user experience and performance on the water.

This comprehensive English-language repair manual provides essential information for the maintenance and repair of your Mercury outboard motor. It details crucial procedures, including recommended service intervals, lubrication requirements for engine oil and gearcase oil, and replacement schedules for components like fuel filters, spark plugs, and water pump impellers. The manual also includes technical specifications and troubleshooting guidance, empowering owners, mechanics, and technicians to effectively maintain the reliability and performance of these marine propulsion units.