This workshop repair manual covers the Yamaha 60C, 70C, and 90C series marine outboard motors. These engines are designed for reliable performance in marine applications, offering a range of horsepower options to suit various boating needs. Yamaha's commitment to engineering excellence ensures these outboard motors are built for durability and efficiency, making them a trusted choice for recreational and professional use. This manual provides comprehensive guidance for maintaining and repairing these robust marine power units. The purpose of this English-language workshop manual is to assist mechanics and technicians of all skill levels in diagnosing and resolving issues, as well as performing essential maintenance on Yamaha 60C, 70C, and 90C outboard motors. It details general information, specifications, periodic inspection and adjustment procedures, and covers key systems including the fuel, power, lower, bracket, and electrical systems. A dedicated trouble-analysis section is included to efficiently identify and address problems, ensuring optimal performance and longevity of your Yamaha marine outboard motor.