This workshop service manual provides comprehensive repair and overhaul information for the Mercury Mariner 30 HP JET outboard engine. Designed for a range of production years, this 4-cylinder, gasoline-powered, water-cooled engine features a jet drive propulsion system. Its robust engineering ensures reliability for various marine applications. This manual serves as an essential resource for automotive technicians, detailing critical maintenance procedures, troubleshooting guides, technical specifications, and safety protocols. It covers all aspects necessary for the proper upkeep and repair of the Mercury Mariner 30 HP JET, ensuring optimal performance and longevity.