STAGE I + CAM, BIG BORE CYLINDERS,
PISTONS, CYLINDER HEADS
& THROTTLE BODY
"I ride hard and want the absolute best performance upgrade available. Try to keep up… I dare you!"
Now that you have the volume, use it the right way. By adding high-flowing ported and matched upper-end components to the bigger engine, you can make sure you're moving as much air and fuel as the engine can take. Stage IV adds more horsepower to the already impressive Stage III upgrade. Designed to satisfy the high RPM, throttle twisting rider, the Stage IV upgrade delivers up to a 52% increase in power. For Milwaukee-Eight engines, this equates to over 120 HP delivered to the rear wheel, installed without removing it from the frame!
Nobody says "no" to more torque and horsepower. Screamin' Eagle components are the key to greater acceleration, increased passing muscle, & more of that rip roaring raw exhaust note that makes power more than a little addicting. Watch to learn more about Screamin' Eagle Stage IV performance upgrades.
Maximize your horsepower - not the labor. Similar to Stage III, the Stage IV upgrade requires removing the engine's top end and swapping the cam. The engine remains in the chassis and no machining or custom fitting is required.
Our Service and Parts teams can work together to help you build out the motor you are looking for to get the power and torque at the levels you want, when you want. It's important to identify what kind of power you want in your motorcycle. Passing power? Off the line? High end? When in doubt, let's go for a ride! Many times we'll have different types of performance kits on demo vehicles or pre-owned vehicles that can be ridden on our test loop to see if it is what you are looking for.
WARRANTY & CAUTION
Harley-Davidson has the engineering expertise, sophisticated dyno lab and complete testing facilities to provide enthusiasts with a line of performance products designed to produce good, solid, reliable horsepower and torque. Engine-related performance parts are intended for the experienced rider only.
Looking for more inspiration? Check out this collection of articles about Customizing Your Harley-Davidson Motorcycle.