This manual covers the Mercury Mariner Marathon outboard motor, a gasoline-powered unit designed for marine propulsion. With a 25 HP engine, this outboard motor features a water-cooled system, CDI ignition, and a carbureted fuel delivery system. It is equipped with a propeller shaft drive and offers a Forward-Neutral-Reverse (F-N-R) gear shift. Depending on the specific model year, it may include manual or electric start and manual or power trim and tilt functionalities. This Service Repair Workshop Manual provides comprehensive instructions for the maintenance and repair of your Mercury Mariner Marathon outboard motor. It details essential procedures, technical specifications, and troubleshooting guidance to ensure optimal performance and longevity. The manual is intended for mechanics and technicians, offering the necessary information to perform routine servicing, address potential issues, and maintain the unit according to manufacturer standards.