This manual covers the Mercury Mariner 70/75/80/90 HP Outboard models manufactured between 1987 and 1993. These early 1987-1993 models are 2-stroke outboards featuring 3-cylinder configurations, carbureted fuel systems, and oil injection. They are designed for reliable performance on the water, offering horsepower options of 70, 75, 80, and 90 HP. The engineering quality of these outboards ensures durability and consistent operation for a variety of boating applications. The workshop service repair manual provided is comprehensive, offering detailed guidance for maintenance and repair. It includes step-by-step procedures for disassembly and assembly, electrical system repair, and troubleshooting. With hundreds of diagrams, drawings, and photos, along with critical notes, cautions, and warnings, this manual is an essential resource for owners, mechanics, and technicians. It covers all aspects of the engine, from the gear housing to the tiller handle, ensuring that the Mercury Mariner outboard can be kept in optimal condition.