This workshop repair service manual provides comprehensive information for the Mercury Mariner Marathon 15 HP outboard motor. Designed for reliable performance, this gasoline-powered, water-cooled engine delivers 15 horsepower through an outboard gearcase with forward, neutral, and reverse gears. While specific model years are not designated, this manual covers all variations of the 15 HP class, ensuring you have the necessary details for maintenance and repair of this robust marine propulsion system. The purpose of this manual is to serve as an authoritative guide for owners and technicians. It details essential maintenance procedures, including service intervals, lubrication, and component specifications. Furthermore, it offers in-depth troubleshooting guidance and technical data necessary for accurate diagnosis and repair. By utilizing the information contained within, users can effectively maintain the longevity and optimal performance of their Mercury Mariner Marathon 15 HP outboard motor.