This service repair manual covers the Yamaha F100B/F100C outboard motor, a water-cooled, inline 4-cylinder engine featuring a 1832cc displacement, SOHC valve mechanism, and Electronic Fuel Injection (EFI). Designed for reliability and performance, this naturally aspirated outboard motor delivers 100 horsepower at 5500 RPM and utilizes a CDI ignition system. Its robust engineering and advanced fuel delivery system make it a dependable choice for various marine applications, suitable for the do-it-yourselfer seeking to maintain their equipment. This comprehensive English-language manual provides detailed service and repair instructions, including high-quality diagrams, to assist in the maintenance and repair of your Yamaha F100B/F100C outboard motor. It covers essential areas such as general information, periodic checks and adjustments, fuel system, power unit, lower unit, bracket unit, and electrical systems. A thorough troubleshooting guide is also included, empowering owners and technicians to effectively diagnose and resolve issues, ensuring optimal performance and longevity of the motor.