This Service Repair Manual covers the Mercury 115HP EFI FourStroke outboard engine manufactured between 2001 and 2002. Engineered for reliability and performance, this FourStroke engine features a multi-point sequential electronic fuel injection (EFI) system and a wet sump lubrication system, delivering 115 horsepower. Its water-cooled design and electric starting system ensure efficient operation. The engine is designed to run on gasoline with various octane ratings, including 87, 91, 92, 93, and race gas. The transmission offers Forward-Neutral-Reverse gear selection with a right-hand rotation propeller, and the option for a counter-rotation propeller. This comprehensive manual provides detailed information essential for the maintenance, repair, and troubleshooting of your Mercury outboard. It includes procedures for routine maintenance tasks such as oil filter changes, fuel filter replacement, water pump impeller service, ignition timing adjustment, and tappet clearance adjustment. Diagnostic information, including wiring diagrams and EFI system troubleshooting, is also covered. Furthermore, the manual details overhaul procedures for major components like the powerhead and lower unit, as well as carburetor rebuilds if applicable. Troubleshooting guides address common issues such as engine starting problems, rough idle, hesitation during acceleration, and excessive smoke, ensuring you can effectively maintain and repair your engine.