This manual covers the Mercury Mariner 150 Magnum III outboard engine, manufactured between 1992 and 2000. This 2-stroke, 4-cylinder engine displaces 153.4 cubic inches (2.5 Liters) and produces 150 horsepower. It features a carbureted fuel system and CD ignition, designed for reliable performance on the water. The engine's robust construction and engineering ensure durability for various marine applications. The purpose of this comprehensive factory service repair manual is to provide detailed information for the maintenance, repair, and troubleshooting of the Mercury Mariner 150 Magnum III. It includes essential technical specifications, lubrication requirements, recommended fuel and spark plug types, and cooling system details. This manual serves as an indispensable resource for owners, mechanics, and technicians to ensure the optimal performance and longevity of their engine.