This manual covers Yamaha outboard motors, specifically models 50G, 60F, 70B, 75C, and 90A. These engines are designed for reliable performance in various marine applications. While specific production years are not detailed, the manual addresses the engineering and operational aspects of these outboard motor designations, providing essential information for their upkeep and functionality. The purpose of this English-language factory service repair workshop manual is to provide comprehensive guidance for all servicing, repair, and maintenance procedures. It includes detailed, easy-to-follow step-by-step instructions, supported by pictures and wiring diagrams. This manual is an indispensable resource for owners, mechanics, and technicians seeking to maintain and repair their Yamaha outboard motors effectively and efficiently.