The MerCruiser Stern Drive Units and Marine Engines Service Manual Number 1 is a comprehensive technical resource designed to guide you through the maintenance and repair of your MerCruiser equipment. Packed with detailed diagrams, illustrations, and manufacturer specifications, this manual provides the information you need to perform a wide range of tasks, from routine tune-ups to complex repairs. The manual is meticulously organized with easy-to-navigate chapters and comprehensive indexing, allowing you to quickly locate the service procedures you need. Detailed illustrations, exploded diagrams, drawings, and photographs guide you through each step of the repair process, ensuring clarity and accuracy. The manual covers a broad spectrum of MerCruiser models, including stern drive units and inboard engines, encompassing both gasoline and diesel models. Specific models covered include: **MerCruiser Stern Drive Engines (MCM):** * MCM 60 - All serial numbers * MCM 80 - All serial numbers * MCM 90 - All serial numbers * MCM 110 - All serial numbers * MCM 120 - Serial numbers 3770649 and below * MCM 140 (6 Cyl.) - All serial numbers * MCM 140 (4 Cyl.) - Serial numbers 3771644 and below * MCM 150 - All serial numbers * MCM 160 - All serial numbers * MCM 165 - Serial numbers 3774864 and below * MCM 888 - Serial numbers 3777489 and below * MCM 190 (V-8) - All serial numbers * MCM 200 (6 Cyl.) - All serial numbers * MCM 215 - All serial numbers * MCM 225 (G.M.) - All serial numbers * MCM 225TR (Ford) - Serial numbers 3779774 and below * MCM 250 (327 CID) - Serial numbers 4767999 and below * MCM 255TR (Ford) - Serial numbers 3838787 and below * MCM 270 - All serial numbers * MCM 310 - All serial numbers * MCM 325 - All serial numbers * MCM 390 - All serial numbers **Transom Assembly and Stern Drive Units:** * MCO - All serial numbers * MCI - All serial numbers * MCTNB/C - All serial numbers * MCINB/C E-2 - All serial numbers * MC80 - All serial numbers * MC90 - All serial numbers * MC 120 - Serial numbers 3780849 and below * MC 140 - Serial numbers 3780849 and below * MC 160 - All serial numbers * MC 165 - Serial numbers 3780849 and below * MC888 - Serial numbers 3784374 and below * MCM 215 H - All serial numbers * MCM 215 E - All serial numbers * MCTR - Serial numbers 3787239 and below * MCII - All serial numbers * MCIII - All serial numbers **MerCruiser Inboard Engines (MIE):** * MIE 30 - All serial numbers * MIE 55 - All serial numbers * MIE 215 - All serial numbers * MIE 225 (G.M.) - All serial numbers * MIE 225 (Ford) - Serial numbers 3750507 and below * MIE 250 (327 CID) - Serial numbers 4767999 and below * MIE 255 (Ford) - Serial numbers 3839487 and below * MIE 270 - All serial numbers * MIE 325 - All serial numbers * MIE 390 - All serial numbers The manual is divided into sections covering essential aspects of MerCruiser maintenance and repair, including: * **General Information:** This section provides basic information about your MerCruiser, including tune-up procedures and lubrication guidelines. * **Removal, Installation, and Alignment:** This section outlines the procedures for removing, installing, and aligning various MerCruiser components, including stern drive units and engines. * **Electrical System:** This section covers the starting system, ignition system, alternator system, instrumentation, and wiring diagrams. * **Fuel Systems:** This section focuses on fuel pumps and carburetors. * **Engine:** This section delves into the mechanical aspects of various MerCruiser engines, covering both in-line and V-8 models. * **Drive Systems:** This section provides detailed information about various MerCruiser drive systems, including the MerCruiser 60-80-90, MerCruiser I, MerCruiser II, MerCruiser III, and MerCruiser II-TR. * **Accessories:** This section covers various accessories like power tilt and trim, steering systems, remote controls, cooling systems, and general accessories. * **Specifications:** This section provides detailed technical specifications for various MerCruiser components. * **Tools:** This section lists the tools required for various repair procedures. This manual serves as an indispensable tool for anyone seeking to maintain and repair their MerCruiser equipment, offering the detailed instruction and technical information necessary to perform a wide range of tasks confidently.

## MerCruiser Stern Drive Units and Marine Engines: A Powerful Legacy in Marine Propulsion The MerCruiser Stern Drive Unit is a highly regarded and widely used propulsion system for recreational boats. Developed and manufactured by Mercury Marine, MerCruiser units combine the power and efficiency of gasoline or diesel engines with a compact, versatile drive system. This system integrates a robust engine with a lower unit, a transmission, and a drive shaft, all encased within a sleek, streamlined housing. This design allows for a shallow draft and increased maneuverability compared to traditional inboard or outboard setups, making them ideal for a diverse range of boat types, from small runabouts to larger cruisers. The MerCruiser brand boasts a rich history, with decades of experience in designing and producing reliable and high-performance marine propulsion systems. Their commitment to innovation has resulted in a range of powerful and efficient engines, from small 4-cylinder models to powerful V8s and even diesel engines. These engines are typically paired with a variety of transmissions and drive units, offering customizability to meet the specific needs of boaters. The MerCruiser system's versatility extends beyond its engine options, with a variety of propellers, steering systems, and accessories available to optimize performance and handling. This comprehensive approach to marine propulsion has made MerCruiser a trusted and respected name in the boating industry, with millions of boats worldwide powered by their reliable and efficient systems.