Yamaha Injection Pump Gear YF1-68515-11-50. Overview. The Yamaha YF1-68515-11-50 Injection Pump Gear is a genuine original equipment manufacturer component designed to support the precise operation of the fuel injection system. This gear helps drive the injection pump, allowing accurate fuel delivery to the engine for consistent performance and efficient combustion.. Proper synchronization between engine components and the injection pump is essential for maintaining smooth engine operation. Over