This workshop service repair manual covers Mercury Mariner 70 HP 3 Cylinder Outboard models manufactured between 1987 and 1993. These engines are known for their reliable 3-cylinder carbureted design, featuring oil injection for enhanced lubrication. This manual provides comprehensive coverage for maintaining and repairing these robust outboard motors, ensuring their continued performance on the water. The purpose of this manual is to serve as a definitive guide for owners, mechanics, and technicians. It includes detailed step-by-step repair procedures, diagnostic information for troubleshooting, and critical technical specifications. Coverage extends to all major components, including the lower unit, gear housing, mid-section, power trim systems, electrical and ignition systems, and tiller handle controls. Hundreds of pages of diagrams, illustrations, and photos are provided to assist with all maintenance and repair tasks.