This workshop service manual covers the Mercury Mariner 30 HP JET outboard engine. Designed for reliable performance, this water-cooled, four-cylinder engine utilizes unleaded gasoline and a jet drive system. While specific production years are not detailed, the Mariner series is engineered for durability and efficiency in marine applications, providing a robust power solution for various boating needs. This comprehensive manual is designed for repair and maintenance. It provides detailed procedures, technical specifications, and essential guidelines to ensure the optimal functioning of your Mercury Mariner engine. Owners, mechanics, and technicians will find this resource invaluable for performing routine servicing, troubleshooting issues, and executing necessary repairs, thereby extending the operational life and performance of the vessel's propulsion system.