This manual covers the Yamaha 20/25 HP Outboard models manufactured between 1997 and 1999. These 2-stroke, water-cooled outboard engines, available in 20 and 25 horsepower variants, are designed for reliable performance on the water. Featuring a CDI ignition system and a direct drive transmission with Forward, Neutral, and Reverse gear selection, these outboards are engineered for durability and efficiency. Specific details regarding displacement, shaft length, and approximate weight are provided within this documentation to assist with identification and application. The purpose of this comprehensive 148-page English Service Repair Manual is to provide detailed guidance for the maintenance, repair, and troubleshooting of your Yamaha 20/25 HP Outboard. It includes essential information on periodic checks, lubrication, fuel mixture ratios, carburetor adjustments, and cooling system maintenance, such as water pump impeller replacement. The manual also addresses common issues related to starting, running, fuel, and electrical systems, offering step-by-step procedures and technical specifications to ensure optimal performance and longevity of your marine engine.