This workshop repair manual covers Mercury Mariner outboard engines, specifically focusing on 4-stroke models with an engine horsepower range of 8-9.9 HP. These engines are engineered for reliability and performance, suitable for a variety of marine applications. Key features include a CDI ignition system, water-cooled operation, and a carburetor fuel delivery system, ensuring efficient power output. The transmission offers Forward, Neutral, and Reverse (F-N-R) gear selection with typical gear ratios around 2.15:1 or 2.08:1. These engines are designed for demanding use, emphasizing durability and consistent operation. This comprehensive English-language workshop service repair manual provides detailed instructions and technical specifications essential for the maintenance and repair of your Mercury Mariner outboard engine. It covers critical areas such as engine oil and gear lube capacities and specifications, recommended fuel types and octane ratings, spark plug types, and trim and tilt system details. By following the procedures outlined within this manual, owners, mechanics, and technicians can ensure the optimal performance, longevity, and safe operation of their 8-9.9 HP Mercury Mariner outboard engines.