This workshop service manual covers Mercury Marine OptiMax outboard engines manufactured from 2010 onwards. Specifically, it details models including the OptiMax 75, 90, 115, 125, and the 115 Pro XS variants, all featuring a 3-cylinder, water-cooled 1.5L engine with Direct Fuel Injection (DFI) and electronic ignition. These engines are engineered for reliable performance and efficiency, incorporating advanced systems such as a Propulsion Control Module (PCM), computer diagnostic capabilities, power trim, and an electric start system. This comprehensive manual provides essential information for maintaining and repairing your Mercury Marine OptiMax engine. It includes detailed maintenance procedures, troubleshooting guides, technical specifications, and critical safety guidelines. Whether you are an owner performing routine upkeep or a technician undertaking complex repairs, this English-language resource offers the in-depth knowledge required to ensure your engine operates at peak performance and longevity.