This Service Repair Workshop Manual provides comprehensive information for the Mercury Mariner 225 HP EFI Outboard. Engineered for reliability and performance, this outboard motor is designed to deliver robust power and efficient operation for a variety of marine applications. Its Electronic Fuel Injection (EFI) system ensures optimal fuel delivery, while the water-cooled design and CDI ignition system contribute to its dependable performance in demanding conditions. The Mariner series is recognized for its quality construction and advanced features, making it a preferred choice for boaters seeking a powerful and trustworthy propulsion system. This manual serves as an essential resource for owners, technicians, and mechanics. It covers detailed maintenance procedures, troubleshooting guides, and technical specifications necessary for the upkeep and repair of the Mercury Mariner 225 HP EFI Outboard. Within these pages, you will find information on lubrication, spark plug specifications, electrical systems, engine performance parameters, and dimensional data. Adhering to the guidelines within this manual will help ensure the longevity, efficiency, and safe operation of your Mercury Mariner outboard.