For the rider demanding no-compromise performance. With the largest displacement and the most power of any Harley-Davidson® Stage Kit, this 121ci to 135ci Stage IV Kit was engineered by the pros at Harley-Davidson to deliver instant arm-stretching torque through the entire rpm range. Made for riders seeking maximum displacement, compression, and flow, it delivers 144 horsepower and 149 ft-lb of torque to the rear wheel! This Stage IV Kit features the finest Screamin’ Eagle® components. Many of these new components were informed by extensive testing by the Harley-Davidson Factory Racing Team for the King of the Baggers racing series. The Stage IV kit consists of: All-new Screamin' Eagle® Extreme CNC-ported cylinder heads, 68mm throttle body and new cast 68mm intake manifold, new SE8-550 high-lift cam and 6.8 g/sec fuel injectors work together to feed the engine large volumes of air and fuel to help maximize power. New forged high-compression pistons and rings are designed to withstand increased combustion forces. Also includes high-performance tappets, new patent-protected 4.31" steel sleeve cylinders, and Screamin' Eagle® Pro Billet Cam Plate and Oil Pump. Screamin’ Eagle and Stage IV badging on the cylinder heads and timer cover highlights the powerplant.
...Read MoreFits '23-later FLHXSE and FLTRXSE and '24-later FLTRXSTSE models. '23-later FLHXSE and FLTRXSE models require separate purchase of P/N 18400117 and 25400103. Requires ECM recalibration with Pro Street Tuner for proper installation. Does not fit California models.