The Mercury Mariner 90 HP outboard engine, produced between 1987 and 1993, represents a robust and reliable option for a variety of marine applications. This early 90s model features a 3-cylinder, water-cooled, 2-stroke engine with carbureted fuel induction and a CDI ignition system, designed for dependable performance on the water. Its electric start system and typical 20-inch long shaft make it a versatile choice for boaters seeking efficient power and straightforward operation. This Workshop Service Repair Manual provides comprehensive guidance for maintaining and repairing your Mercury Mariner 90 HP outboard. It covers essential areas including detailed maintenance procedures, troubleshooting common issues, and crucial technical specifications. By following the instructions and recommendations within this manual, owners and technicians can ensure optimal performance, longevity, and safety of the engine.