This Service Repair Workshop Manual covers Mercury Marine Outboard Engines manufactured between 1987 and 1993, specifically models ranging from 70HP to 90HP. These 2-stroke engines are designed for marine propulsion, featuring a water-cooled system, carbureted fuel delivery, and CDI ignition. With a focus on reliability and performance, these outboards are engineered to provide dependable power for a variety of boating applications. The manual provides comprehensive information for maintaining and servicing these robust marine powerplants. The purpose of this manual is to provide detailed instructions and specifications for the maintenance, repair, and troubleshooting of your Mercury Marine outboard engine. It includes all necessary A-Z repair procedures, diagnostic information, and technical specifications, along with safety guidelines. Whether you are a seasoned technician or an owner performing routine maintenance, this guide offers the essential knowledge to keep your engine operating at peak performance. Printable diagrams and detailed procedures are included to assist with all service tasks.