This workshop service repair manual covers the Mercury Mercruiser, an internal combustion engine family known for its reliability and robust engineering, designed for marine applications. Featuring a 4-cylinder, inline engine block with a displacement of 181 cubic inches (2.97 liters), this powertrain typically delivers between 135-145 horsepower. It is equipped with a propeller drive system, commonly found in stern drive or inboard/outboard configurations, and utilizes gasoline as fuel. Depending on the specific model year, fuel delivery can be either carbureted or fuel injected, and various gear ratios are available to suit different operational needs. This comprehensive manual is designed to provide essential information for the maintenance and repair of your Mercury Mercruiser engine. It details crucial procedures for lubrication, including recommended oil types and capacities, as well as guidance on the cooling and ignition systems. Technical specifications, electrical system details such as alternator output, and troubleshooting advice are also included. This resource serves as an indispensable tool for owners, mechanics, and technicians, ensuring the continued optimal performance and longevity of the Mercruiser engine.