This manual covers Mercury Mariner Outboard models with horsepower ratings of 40, 50, 55, and 60. It specifically applies to units with United States serial numbers 0G531301 and above, and Belgium serial numbers 09974454 and above. These outboards are engineered for reliable performance and are designed for a variety of marine applications. The manual details components such as the fuel pump, carburetor, oil injection, powerhead, mid-section, and lower unit variations including Bigfoot and Jet Drive. The purpose of this Service Repair Manual is to provide comprehensive guidance for the maintenance, repair, and troubleshooting of your Mercury Mariner Outboard. It includes detailed procedures, diagnostic support, and parts breakdowns, all enhanced with clear, zoomable illustrations and exploded views. This manual is an essential resource for owners, mechanics, and technicians to ensure the optimal performance and longevity of the outboard engine.