This manual covers the Mercury Mariner outboard engine, a powerful and reliable choice for marine propulsion. Featuring a 225 HP V6 engine with 3.0L displacement and Electronic Fuel Injection (EFI), this water-cooled unit is engineered for performance and efficiency. Its robust construction and advanced ignition system ensure dependable operation across various watercraft applications. This Service Repair Manual provides comprehensive guidance for the maintenance, repair, and technical understanding of your Mercury Mariner outboard. It details essential procedures, specifications, and troubleshooting steps to help owners and technicians keep the engine in optimal condition. Coverage includes lubrication, fuel requirements, and other critical aspects necessary for ensuring the longevity and peak performance of your Mercury Mariner engine.