This Service Repair Manual covers the Mercury Mariner 3.0L Marathon Outboard, a V6, water-cooled outboard motor designed for marine propulsion. Engineered for reliability, this outboard motor likely features fuel injection and an electronic ignition system, providing efficient power for various boating applications. Its robust construction and advanced systems are testament to Mercury's commitment to performance and durability on the water. This comprehensive manual serves as an essential guide for maintaining and repairing your Mercury Mariner 3.0L Marathon Outboard. It details critical maintenance procedures, technical specifications, and troubleshooting steps necessary for optimal performance and longevity. Owners, technicians, and mechanics will find invaluable information on engine systems, fluid capacities, electrical components, and scheduled service intervals, ensuring the continued seaworthiness of the vessel.