This workshop service repair manual covers Mercury Mariner outboard motors. These engines are known for their reliable performance and are designed for a wide range of boating applications. The Mercury Mariner outboard motor, typically a 20 HP gasoline-powered, water-cooled unit, offers robust engineering for its class. While specific model years are not detailed, this manual is applicable to serial numbers starting from US 0G044027 and Belgium 09807909 and above, ensuring comprehensive coverage for a significant production run. The purpose of this English-language manual is to provide detailed information for the maintenance, repair, and troubleshooting of your Mercury Mariner outboard motor. It includes essential procedures for scheduled maintenance, technical specifications, and diagnostic guidance. By utilizing the information within this manual, owners, mechanics, and technicians can ensure the optimal performance, longevity, and safety of the outboard motor. The manual covers various aspects, including engine operation, fuel systems, ignition, and drive systems, empowering users with the knowledge required for effective upkeep.