Provides service, repair and maintenance information for 1990-1993 Mercury 3-275hp outboard models including 3 hp, 3.3 hp, 4 hp, 5 hp, 8 hp, 9.9 hp, 15 hp, 20 hp, 25 hp, 40 hp, 50 hp, 60 hp, 75 hp, 90 hp, 100 hp, 115 hp, 135 hp, 150 hp, 150XR4, 150XR6, 150XRi, 175 hp, 175XRi, 200 hp, 200XRi, 250 hp, and 275 hp motors. Includes general information for each model, tools and techniques, troubleshooting, lubrication, maintenance and tune-up, timing, synchronizing and adjusting, fuel system, ignition and electrical systems, power head, lower unit gear housing, power trim and tilt systems, oil injection system, manual rewind starter and complete wiring diagrams. Features 640 illustrated pages.