This service repair manual covers the Mercury Mariner outboard motor, a powerful engine designed for marine applications. While specific production years and detailed features are not specified, this manual addresses models equipped with Electronic Fuel Injection (EFI) and a 250 HP power output. The engineering of Mercury outboard motors is recognized for its reliability and performance on the water, providing a robust solution for various boating needs. This comprehensive manual provides essential information for the maintenance and repair of your Mercury Mariner outboard motor. It details critical procedures, technical specifications, and troubleshooting guidance necessary for optimal performance and longevity. Owners, technicians, and mechanics will find this document invaluable for understanding the intricacies of the engine's systems, including ignition, fuel, and power trim, ensuring the vessel remains in peak operating condition.