This Service Repair Manual covers the Mercury Mariner outboard motor, a 2-stroke, water-cooled engine with a 30 HP output from its 2-cylinder configuration. Designed for reliable performance on the water, this motor features a carbureted fuel system and CDI ignition for efficient operation. Its robust construction and engineering ensure durability for various marine applications. This manual provides comprehensive guidance for maintaining and repairing your Mercury Mariner outboard motor. It details essential procedures for lubrication, scheduled servicing including spark plug and water pump impeller replacement, and gearcase oil changes. Technical specifications, troubleshooting tips, and safety guidelines are also included, empowering owners and technicians to keep the engine in optimal condition.