This workshop repair manual covers the Mercury Mariner, an outboard engine designed for marine propulsion. Featuring a 2-cylinder gasoline engine with a 40 horsepower rating, this water-cooled unit is equipped with a carbureted fuel system and commonly includes an electric start and power trim and tilt capabilities. Its robust engineering prioritizes reliability and performance for a wide range of boating applications. This comprehensive manual provides essential information for the service, maintenance, and troubleshooting of your Mercury Mariner outboard. It details critical procedures, technical specifications, and diagnostic guidance necessary for maintaining optimal performance and longevity. Owners, technicians, and mechanics will find the step-by-step instructions and diagrams invaluable for ensuring the safe and efficient operation of the engine.