This manual pertains to the Mercury Mariner 30JET HP outboard motor, a gasoline-powered, water-cooled, 4-cylinder engine designed for marine applications. While specific production years are not detailed, this service repair manual covers essential aspects of this model. The Mariner 30JET HP is engineered for reliable performance on the water, offering a robust solution for various boating needs. This comprehensive English-language service repair manual provides detailed information for the maintenance and repair of the Mercury Mariner 30JET HP. It covers critical procedures including lubrication, recommended service intervals, and specific maintenance tasks such as spark plug, fuel filter, impeller, and gearcase lube replacement. This guide is an indispensable resource for owners and technicians seeking to ensure the optimal performance and longevity of their outboard motor.