This Service Repair Manual covers the Mercury Mariner outboard engine, produced between 1988 and 1993. This specific model run is known for its robust engineering, designed for reliable performance in marine environments. The engine features a 4-cylinder, naturally aspirated, water-cooled configuration, delivering 100 horsepower through a carbureted fuel system and an outboard lower unit with forward, neutral, and reverse gears. Its construction emphasizes durability and efficiency, making it a dependable choice for various boating applications. This manual provides comprehensive guidance for the maintenance, repair, and technical understanding of your Mercury Mariner outboard. It details essential procedures, including lubrication, scheduled maintenance intervals for components like spark plugs and water pump impellers, and troubleshooting common issues. Technical specifications and safety guidelines are also included to ensure proper operation and longevity. Owners, mechanics, and technicians will find this resource invaluable for keeping the engine in optimal condition.