Mercury - Fuel Injector MerCruiser MPI Series Precision-Matched Marine Injector 861260T. Overview. There's a certain satisfaction in hearing a MerCruiser engine settle into a clean, steady rhythm-the kind of smooth idle or crisp acceleration that tells you the fuel system is working exactly as it should. When you spend weekends on the water, you come to appreciate the parts that keep that feeling alive. The Mercury Marine part number 861260T Fuel Injector is one of those components. It delivers