This manual covers the Mercury Mariner 50 HP Bigfoot, a 4-stroke gasoline engine designed for marine applications. Known for its robust construction and reliable performance, this engine is engineered to provide consistent power and efficiency for a variety of boating needs. Its water-cooled system ensures optimal operating temperatures, contributing to its durability and longevity on the water. The purpose of this English-language repair service manual is to provide comprehensive guidance for the maintenance, repair, and troubleshooting of the Mercury Mariner 50 HP Bigfoot. It details essential procedures, technical specifications, and safety information required to keep the engine in optimal working condition. This resource is intended for owners, technicians, and mechanics seeking to understand and maintain the engine's complex systems, ensuring its continued performance and reliability.