The Mercury-Mariner 50HP 60HP 4-Stroke outboard motor, manufactured in 2001, represents a robust and reliable option for marine propulsion. Available in Bigfoot and non-Bigfoot variants, this engine is engineered for dependable performance across a range of applications. Its 4-stroke DOHC design, coupled with multi-point sequential electronic fuel injection or carburetor systems on applicable models, ensures efficient power delivery and fuel economy. Designed for water cooling and featuring a wet sump lubrication system, these engines are built for durability and sustained operation in demanding marine environments. This service manual provides comprehensive guidance for the maintenance and repair of your Mercury-Mariner 50HP 60HP 4-Stroke outboard motor, serial number range 0T178500 and above. It covers essential procedures including spark plug and fuel line replacement, engine and gear oil changes, water pump impeller service, ignition timing adjustment, and tappet clearance adjustment. Detailed technical specifications, troubleshooting information, and safety guidelines are also included to assist owners, mechanics, and technicians in keeping the engine in optimal condition and ensuring its longevity.