This workshop service repair manual covers Johnson Evinrude Outboards 100 HP models manufactured between 1973 and 1990. These outboard motors are recognized for their robust engineering and reliable performance, making them a popular choice for various marine applications. This manual provides comprehensive information to ensure these engines operate at their peak efficiency and longevity. The purpose of this manual is to serve as an authoritative guide for owners, mechanics, and technicians. It details essential maintenance procedures, including lubrication, tune-ups, and system-specific servicing for the fuel, ignition, electrical, power head, gearcase, and power trim and tilt systems. Furthermore, it offers in-depth troubleshooting and diagnostic guidance, supported by diagrams, illustrations, photographs, wiring diagrams, step-by-step instructions, critical specifications, and parts identification to facilitate accurate repairs and maintenance.