This manual covers the Yamaha 15ESD Outboard, a 1990 model from the first generation. This 2-stroke outboard engine features a 212 cc displacement, producing 15 horsepower across two cylinders. Known for its robust engineering and reliability, the 15ESD is designed for dependable performance in marine applications. Its specifications include a 54 mm bore x 46 mm stroke, a compression ratio of 6.8:1, and a Mikuni VM carburetor. The transmission utilizes an outboard gearcase with a 2.00:1 gear ratio and shaft drive, available in short or long shaft configurations. The purpose of this English-language Service Repair Maintenance Manual is to provide comprehensive guidance for the Yamaha 15ESD Outboard. It details essential maintenance procedures, including recommended oil types and viscosity, spark plug gap settings, and fuel mix ratios. The manual also offers troubleshooting information and technical specifications, organized with step-by-step procedures and exploded diagrams for clarity. This resource is invaluable for owners, mechanics, and technicians seeking to ensure the optimal performance, longevity, and safe operation of their Yamaha 15ESD outboard motor.