This comprehensive service and repair workshop manual is a valuable resource for owners and mechanics working on 1978-1982 Mercury Mercruiser Marine Engines Number 4 Stern Drive Units, specifically models MCM 120, 140, 165, 470, 485, 898, 228, and 260 with serial numbers ranging from 4891650 to 6216686. It covers a wide range of topics, including detailed instructions for servicing and repairing the drive unit, transom plate assembly, power trim, and power steering systems. The manual features clear illustrations and step-by-step instructions, making it an ideal tool for both experienced mechanics and DIY enthusiasts. The manual provides thorough troubleshooting guidance, enabling you to identify and resolve issues efficiently. You'll find in-depth coverage of the drive shaft housing assembly, gear housing assembly, and transom plate assembly, including detailed explanations of their components and functions. With its comprehensive service bulletins, you'll stay informed about the latest updates and recommendations for maintaining your Mercury Mercruiser engine. This manual equips you with the knowledge and guidance needed to keep your marine engine running smoothly and reliably.

The 1978-1982 Mercury Mercruiser MCM 120-260 Service Repair Workshop Manual is an indispensable resource for owners, mechanics, and enthusiasts of Mercury Mercruiser stern drive units manufactured during those years. This manual encompasses a comprehensive collection of technical information and detailed instructions for maintaining, troubleshooting, and repairing the MCM 120, MCM 140, MCM 160, MCM 188, MCM 200, and MCM 260 models. It provides a complete understanding of these engines' design, components, operation, and potential issues, enabling users to diagnose and address a wide range of problems effectively. The workshop manual serves as a comprehensive guide, offering step-by-step procedures for performing various maintenance tasks, such as oil changes, filter replacements, and tune-ups. It also covers detailed repair procedures for common issues like engine starting problems, overheating, fuel system malfunctions, and electrical system errors. Furthermore, the manual includes detailed schematics, diagrams, and specifications for all major components, providing a visual understanding of the engines' internal workings and aiding in troubleshooting and repairs. This invaluable resource empowers users to confidently diagnose and rectify issues with their Mercruiser stern drive units, ensuring optimal performance and longevity.