This manual covers outboard motors from 1973 to 1990, with a specific focus on the 100 HP models. These robust outboard engines are engineered for reliability and performance, making them a trusted choice for a wide range of marine applications. The comprehensive coverage provided ensures that owners and operators can understand and maintain these units effectively, preserving their operational integrity and longevity on the water. This Service Repair Manual is an essential resource for anyone involved with outboard motors. It provides detailed procedures for lubrication, maintenance, tune-ups, engine synchronization, and linkage adjustments. The manual also thoroughly covers the fuel, ignition, electrical, power head, gearcase, and power trim & tilt systems, along with troubleshooting guidance, tools, techniques, and general information. With hundreds of pages of detailed instructions and diagrams, this manual is designed to assist owners and technicians in performing all necessary service and repair tasks.