This manual covers the Yamaha 9.9 HP and 15 HP outboard engines manufactured between 1984 and 1992. These 2-stroke, water-cooled engines feature a displacement of 212 cc and utilize a CDI ignition system and carburetor for fuel delivery. Designed for reliability and performance, these outboards are suitable for a variety of marine applications. The engines offer power outputs of 9.9 HP or 15 HP at 5000 RPM, with a 2-cylinder configuration and a pre-mix gasoline/oil lubrication system. They are available with short or long shaft options and feature a Forward, Neutral, Reverse gear selection with single gear reduction. This Service Repair Workshop Manual provides comprehensive guidance for the maintenance and repair of your Yamaha outboard engine. It details essential procedures, technical specifications, and troubleshooting steps necessary to keep your engine operating efficiently. Topics covered include engine specifications, lubrication requirements, fuel and oil mixture ratios, spark plug gap settings, and recommended fuel octane. This manual is an indispensable resource for owners, mechanics, and technicians seeking to ensure the longevity and optimal performance of their Yamaha 9.9 HP / 15 HP outboard.