This factory service repair manual covers Yamaha Outboard Motors across the 50G, 60F, 70B, 75C, and 90A series. These 2-stroke outboard engines are designed for reliable performance in various marine applications. While specific model years are not detailed, this manual applies to multiple production years within these series, offering comprehensive guidance for their upkeep and repair. The engineering quality and reliability inherent in Yamaha outboards are supported by the detailed information contained within this resource. The purpose of this manual is to provide owners, mechanics, and technicians with the necessary information to maintain and repair their Yamaha outboard motors. It includes step-by-step instructions, detailed illustrations, wiring diagrams, troubleshooting guides for common fixes, and maintenance tips. Key areas covered include engine specifications, fuel systems, gearcase information, lubrication, periodic checks and adjustments, and electrical system analysis. This comprehensive guide ensures that the motors can be kept in optimal working condition.