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RK-3931
$149.99 USD
MSRP $262.99 43.0% Off
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K&N RK-3931

Custom Assemblies > Intake System-Harley Davidson
  • Designed to increase horsepower & torque
  • Dyno-tuned velocity stack
  • Excellent Air Filtration
  • Washable and reusable lifetime air filter
  • Not legal for highway use in states adopting California emission regulations
K&N Air Cleaner Assemblies are designed to get more horsepower from your Harley-Davidson® motorcycle. These air cleaner assemblies replace the stock air filter and backplate with an oversized K&N Air Filter and custom aluminum backing plate. These assemblies utilizes the stock cover to maintain stock appearance.

[More Information on High-Flow Air Intake Systems for Harley-Davidson Motorcycles]

Product Specifications

Estimated Horsepower Gain6.54 HP @ 5100 RPM
Air Filter ColorRed
Air Filter Height2.125 in (54 mm)
Air Filter MaterialCotton Gauze
Air Filter Outlet ShapeNot Flanged
Air Filter ShapeUnique
California RestrictedNot legal for sale or use in California
Clamp MaterialNo Clamps Required
Clamp StyleNo Clamps Required
Clamps IncludedNo Clamps Included
ColorRed
Filter MaterialCotton Gauze
Inlet Diameter2.406 in (61 mm)
Mounting Hardware IncludedYes
Neck Flange2.406 in (61 mm)
Overall Height2.5 in (64 mm)
Product Box Height4.88 in (124 mm)
Product Box Length11.75 in (298 mm)
Product Box Width9.5 in (241 mm)
Product StyleMotorcycle Intake System
Replacement FilterE-3975
Size9 Inch
Street Legal In All US States No
StyleTeardrop
Top Material/FinishAluminum
Top StyleMetal
TUV Approved (Europe)No
Weight3.1 lb (1.4 kg)
Horsepower gains based on similar vehicle dynamometer test. Results will vary.

Customer Feedback

THE K&N AIR FILTER THAT I ORDERED WAS SHIPPED OUT AND RECEIVED IN A TIMELY MATTER. I WOULD RECOMMEND IT TO ANYONE LOOKING TO UPGRADE FROM THEIR STOCK FILTER TO A HIGH PERFORMANCE FILTER. AWESOME FILTER!! THIS WILL GO ON MY 2013 HARLEY DAVIDSON STREETGLIDE.

Mike Miston
Michigan
Fast delivery. Chrome finish is a plus. The external socket fitting will make an easy removal on my next oil change. I trust the engineering K & N designs into their products to filter out contaminates to protect my 2006 Harley Davidson 35th Anniversary superglide motorcycle.

Michael Snow
Chicago, Illinois
I have used K&N filters for all of my Harley Davidson applications. I just replaced the HD filter with this and am pleased as usual.

Bill White
Hot Springs, Arkansas