This manual covers Mercury Mariner Outboard Motors produced between 1965 and 1989, specifically models ranging from 45 to 115 horsepower. These 2-stroke, 3 and 4-cylinder engines were engineered for reliable performance on the water. This comprehensive guide provides detailed information essential for understanding, maintaining, and repairing these robust marine powerplants, ensuring their continued operational excellence. The purpose of this factory service repair manual is to provide owners and technicians with complete, step-by-step instructions and detailed illustrations for all service and repair procedures. It covers critical areas including safety, tuning, engine components such as the powerhead, fuel and ignition systems, electrical systems, remote controls, power trim/tilt, and the lower unit. This 557-page English-language manual is designed to empower users to perform maintenance and repairs effectively, saving time and money while deepening their knowledge of their Mercury Mariner outboard motor.