This workshop service manual covers the Mercury Mariner 250 HP EFI Outboard, a powerful V6 engine designed for demanding marine applications. Known for its robust construction and reliable performance, this outboard utilizes Electronic Fuel Injection (EFI) to optimize power delivery and efficiency. While specific production years are not detailed, this manual applies to the 250 HP EFI Outboard model, providing comprehensive information for its operation and upkeep. This English-language workshop service manual is designed for the repair and overhaul of the Mercury Mariner 250 HP EFI Outboard. It provides detailed procedures, technical specifications, and essential guidelines to assist owners, mechanics, and technicians in maintaining the engine's optimal performance and longevity. The manual covers various aspects of the engine and its systems, ensuring that users have the necessary information for effective troubleshooting and repair.