This Stage IV Kit was developed to deliver maximum horsepower from the Milwaukee-Eight® engine - all the way to the redline. The system-matched combination of larger displacement cylinders, free flowing CNC-Ported cylinder heads and a cam with the highest available valve lift are the starting point to building the perfect engine for the performance junkie. Designed for a high level of flexibility, this package is ideal for riders who like to comfortably cruise at lower rpm but still have plenty of arm-pulling acceleration when you whack the throttle. Kit includes CNC Ported Cylinder Heads with Performance Valve Springs, 64mm Throttle Body, High Flow Injectors (5.5g/s), 4.075" Bolt-On Cylinders, Forged 11:1 High Compression Aluminum Coated Pistons and Rings, SE8-515 Cam, Cam Bearing Upgrade, High Performance Tappets, Multi-layer Coated Head Gaskets, High Capacity Clutch Springs (1200N), High Capacity Clutch Disks and most necessary gaskets and seals.
- Stage IV Kit 107CI to 114CI - Air/Oil-Cooled
- Black with Highlighted Fins - Matches Original Equipment non-CVO™ models
- Delivers up to 52% more power when compared to the Original Equipment engine configurations
- Delivers increased response throughout the entire RPM range
- Maintains flat torque curve from cruising RPM to redline
- Can be installed without removing the engine from the chassis
- Retains Original Equipment Factory Warranty
Dealer Install RecommendedYes
Warranty1 year limited warranty – Go to www.h-d.com/warranty for full details
Requires ECM CalibrationYes
Certifications50-State U.S. EPA compliant
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In The BoxClick the Description tab above for details
Sold SeparatelyClick the Fitment tab above for details
Upgrade Stage LevelStage IV
Fits '18-later Softail® and '17-later Touring models equipped with air/oil cooled 107CI Milwaukee-Eight® engine. Does not fit Trike models. Requires separate purchase of Cam Drive Retention Kit P/N 25566-06. Installation may require Cam Spacer Kit P/N 25928-06. For ’17-’18 Touring models, installation of Oil Pump Cover P/N 62400206 is recommended (sold separately). All models require ECM calibration with Screamin' Eagle® Pro Street Tuner for proper installation. Pending approval for use in California on '20 models. Refer to H-D®.com/shop for status.
- Deluxe FLDE
- Fat Boy FLFB
- Heritage Classic FLHC
- Sport Glide FLSB
- Softail Slim FLSL
- Street Bob FXBB
- Breakout FXBR
- Fat Bob FXFB
- Low Rider FXLR
- Road King FLHR
- Road King Special FLHRXS
- Electra Glide Ultra Classic FLHTCU
- Street Glide FLHX
- Street Glide Special FLHXS
- Road Glide FLTRX
- Road Glide Special FLTRXS
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- These Screamin' Eagle® products are 50-State U.S. EPA compliant for sale and use on all applicable vehicles, including those that are pollution controlled. See Genuine Motor Parts and Accessories or Screamin' Eagle Accessories catalog for fitment information. Screamin' Eagle Performance products are intended for the experienced rider only.
When installed by an authorized Harley-Davidson® Dealer at the time of vehicle delivery, compliant kits do not impact the vehicle’s limited warranty.
Q & A
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FLHXS Milwaukee 8 stage IV kit
Why can't you put a Stage IV kit on a tri-glide with a M8 engine? It's the same engine as an Ultra limited or street glide!
Please Hold Your Iron Horses