The Mercury Mariner 100 HP, produced between 1988 and 1993, represents the first generation of this powerful outboard motor. Engineered for reliable performance on the water, this four-cylinder, naturally aspirated, carbureted engine delivers 100 horsepower. Its water-cooled system ensures efficient operation, while the outboard lower unit with forward, reverse, and neutral gears provides versatile control. This model is designed to offer dependable propulsion for a variety of boating applications, emphasizing robust construction and straightforward functionality. This Factory Service Repair Manual provides comprehensive guidance for the Mercury Mariner 100 HP outboard motor. It covers essential maintenance procedures, including lubrication with 2-stroke outboard oil, and offers insights into troubleshooting common issues. Detailed technical specifications, such as engine configuration and performance capabilities, are included to aid in understanding the motor's operation. This manual is an indispensable resource for owners, mechanics, and technicians seeking to maintain, repair, and optimize the longevity and performance of their Mercury Mariner 100 HP motor.