This comprehensive factory service repair manual is your essential guide for maintaining and repairing your Mercury Mariner 75 HP Marathon 3-cylinder outboard motor, covering models from 1987 to 1993. The manual provides detailed information and step-by-step instructions, mirroring the resources utilized by authorized dealers. You'll find a wealth of detailed illustrations and clear explanations to confidently tackle any repair or maintenance task. This manual is your one-stop resource for all things related to your outboard motor, including: * **General Information and Specifications:** Get acquainted with your engine's technical details, specifications, and general operating principles. * **Electrical and Ignition:** Master the intricacies of your engine's electrical system, understand the ignition system, and troubleshoot issues related to batteries, charging systems, and starting. * **Timing/Synchronizing and Adjusting:** Learn how to accurately time and synchronize your engine for optimal performance and efficiency. * **Wiring Diagrams:** Decipher the electrical layout of your engine with clear and detailed wiring diagrams. * **Fuel System and Carburetion:** Get a thorough understanding of your fuel system, from fuel lines to carburetors, enabling you to diagnose and repair fuel-related issues. * **Oil Injection System:** Learn how to maintain and troubleshoot your engine's oil injection system for proper lubrication. * **Powerhead (3-Cylinder Engines):** Dive deep into the intricacies of your engine's powerhead, including detailed descriptions, diagrams, and repair procedures. * **Lower Unit:** Understand the construction and operation of the lower unit, including gear housing, mid-section, shock absorber, and power trim. * **Design I (Side Fill Reservoir) and Design II (Aft Fill Reservoir):** Learn the specifics of both reservoir designs for your engine. * **Single Ram:** Gain knowledge of your engine's single-ram steering system. * **Outboard Motor Installation/Attachments:** Get expert advice on proper installation and attachment of your outboard motor, including engine attachments, tiller handle, and co-pilot. With this manual, you'll have everything you need to confidently maintain, repair, and troubleshoot your Mercury Mariner 75 HP Marathon 3-cylinder outboard motor.

The Mercury Mariner 75 HP Marathon 3 Cylinder outboard motor, produced from 1987 to 1993, was a popular choice for recreational boaters seeking a reliable and powerful engine. This model, part of the Marathon series, was known for its robust construction and durability, making it a favorite among anglers and watersport enthusiasts. The 75 HP output was achieved through a 3-cylinder, 75 cubic inch displacement engine, boasting a large bore and a relatively short stroke for its class. This design resulted in a smooth and efficient power delivery, well-suited for a variety of boat types, from small fishing boats to larger runabouts. The Marathon series focused on simplicity and ease of maintenance, featuring a straightforward design with readily accessible components. The overall design emphasized a balance between performance and ease of use, making it a compelling choice for both novice and experienced boaters alike. The Mercury Mariner 75 HP Marathon 3 Cylinder outboard motor was equipped with a number of features designed to enhance its performance and longevity. A closed-loop cooling system ensured consistent operating temperatures, protecting the engine from overheating and extending its lifespan. The powerhead featured a durable cast iron construction, further enhancing its durability and resistance to wear and tear. The engine also included a built-in oil filter, offering improved lubrication and engine protection. The Mariner 75 HP Marathon 3 Cylinder engine was known for its smooth running characteristics and excellent fuel economy, making it an efficient and enjoyable choice for a wide range of boating activities. With its reliable performance and user-friendly design, the Mercury Mariner 75 HP Marathon 3 Cylinder outboard motor remains a popular choice for boaters looking for a dependable and capable engine for their water adventures.