The Mercury Mariner 225 HP DFI Optimax is a Direct Fuel Injection (DFI) outboard engine designed for reliable performance. This engine incorporates advanced DFI technology for efficient fuel delivery and optimal power output. Its robust construction and engineering ensure durability and consistent operation, making it a dependable choice for various marine applications. This Service Repair Manual provides comprehensive guidance for the Mercury Mariner 225 HP DFI Optimax. It covers all aspects of maintenance, repair, and technical specifications, including detailed step-by-step instructions, hundreds of photos and illustrations, and complete disassembly procedures. The manual is designed to assist both do-it-yourself enthusiasts and experienced mechanics in maintaining the engine's optimal performance and longevity.