This workshop service repair manual covers the Mercury Mariner outboard motors produced between 1997 and 2003. These engines, available in 75, 90, 100, 115, and 125 horsepower variants, are part of the Marathon Seapro Jet series and are designed for robust marine propulsion. The Mercury Mariner line is recognized for its dependable performance and engineering quality, making it a trusted choice for various boating applications. This manual provides in-depth information to ensure these outboards operate at their peak efficiency and longevity. The purpose of this comprehensive manual is to serve as an essential resource for owners, technicians, and mechanics. It details all aspects of maintenance, repair, and technical specifications for the Mercury Mariner outboard motors. Within these pages, you will find step-by-step procedures for routine maintenance, tune-up guidance, lubrication information, and detailed troubleshooting charts to diagnose and resolve common issues. The manual also includes technical specifications and information on the outboard lower unit and jet drive systems, empowering users to perform necessary upkeep and repairs effectively.