Go big or go home. With the largest displacement of any Harley-Davidson Stage Kit, this 107CI to 128CI Stage IV Kit is designed to deliver maximum horsepower all the way to the redline. Packaged with patent-protected cylinder technology, it allows for the largest bolt-on engine upgrade to any Milwaukee-Eight motor. Features new CNC-ported heads with 1mm bigger valves and fully machined combustion chambers. Coupled with the kit's high-lift SE8-517 cam, high compression pistons and a 64mm throttle body and intake manifold, this combination delivers a thrilling 135ft-lb of torque and 124 HP rear-wheel output when paired with Screamin' Eagle® Street Cannon Mufflers for 131 kit customers. Its designed to run wide open at high-end RPMs and provide a significant boost of torque from cruising speed. Youll feel the difference as soon as you twist the throttle.
- Delivers increased response throughout the entire RPM range
- Provides thrilling acceleration when twisting the throttle
- Maintains flat torque curve from cruising RPM to redline
- Can be installed without removing the engine from chassis
- Includes CNC Ported Cylinder Head with CNC machined chamber and 1mm larger valves, 131 Stage IV Timer cover, SE8-517 High-Lift Cam, Forged High Compression Pistons
- Also includes High Performance Cam Bearing and High Performance Tappets, 4.31" Steel Sleeve Cylinders, 64mm Throttle Body and Cast Manifold, High Flow Injectors (5.5 g/sec)
- Pending 49-State U.S. EPA compliant