The Mercury Mariner 40 Marathon is a robust 2-stroke outboard motor, engineered for reliable performance on the water. Featuring a 2-cylinder configuration and delivering 40 horsepower, this motor is designed for a variety of marine applications. Its construction emphasizes durability and efficiency, making it a dependable choice for boaters seeking consistent power and smooth operation. The Mariner 40 Marathon benefits from a water-cooled system and CD ignition for optimal performance and longevity. This Service Repair Manual provides comprehensive guidance for maintaining and repairing your Mercury Mariner 40 Marathon outboard motor. It covers essential procedures, including lubrication, fuel-oil mixture recommendations, and recommended intervals for component replacement such as spark plugs and water pump impellers. Detailed technical specifications, troubleshooting tips, and safety guidelines are included to assist owners, mechanics, and technicians in ensuring the motor operates at peak condition.