This workshop service repair manual covers the Mercury Mariner 225 HP outboard motor, a powerful and reliable gasoline-powered engine designed for marine applications. Featuring a water-cooled system, CDI ignition, fuel injection, and electric start, this outboard motor is engineered for optimal performance and durability on the water. Its robust construction and advanced features ensure a dependable boating experience for a variety of watercraft. This comprehensive manual provides essential information for the maintenance, repair, and troubleshooting of your Mercury Mariner outboard. It details critical procedures, including recommended lubrication for the engine and gearcase, break-in periods, and regular service intervals. Technical specifications, safety guidelines, and system overviews are also included to assist owners, mechanics, and technicians in keeping this high-performance engine in peak operating condition.