K&N RK Series Air Cleaner Adds Power with Classic Style for 2013-2015 Harley Softail

The Harley-Davidson® Softail® family of motorcycles pays tribute to early hard tail Harley-Davidson motorcycles by giving the hardtail look with a pair of hidden shocks under the trans

K&N increased power for 2013-2015 Softail models by replacing the stock assembly with an open element high-flow K&N air filter, and bolted-in velocity stack, mounted to a powder coated aluminum backing plate

The Harley-Davidson^® Softail^® family of motorcycles pays tribute to early hard tail Harley-Davidson motorcycles that pre-date the 1958 Duo-Glide. The classic hardtail look is accomplished by tucking the rear shock absorbers underneath the transmission while a triangular swingarm pivots at the top near the rear seat. Harley-Davidson has utilized the Softail design to build bikes that give the appearance of a stripped down chopper, like the FXSB Breakout, or for the timeless look of the Harley FLST Heritage Softail. No matter whether a Softail is ridden like a bare-bones hotrod, or a classic leather bagged touring bike, a little extra power is always a good thing.

The 2013, 2014, and 2015 Harley-Davidson Softail family of big twin motorcycles is powered by the Twin-Cam 103 cubic-inch engine. The Twin-Cam engine was first introduced in 1998 (1999 for Softail models) and has evolved over its 17 year production life. Displacement has increased from 88 cubic-inches, to 103. The traditional single carburetor has been updated to modern fuel injection. Some Twin-Cam engines even feature twin cooling with hidden radiators designed to cool the cylinder heads without upsetting the classic look of a Harley V-Twin. Yet despite these advances in technology, these bikes are equipped from the Milwaukee factory with a rather low-tech and restrictive air filter and air cleaner housing design.

The custom K&N 2013-2015 Softail air cleaner backing provides a solid mounting surface and an integrated crankcase breather system for a trick look that keeps crankcase blow by where it belongs

K&N RK Series air cleaner for 2013-2015 Harley Softails, including the Breakout, Deluxe, Fat Boy, & Heritage remains hidden behind the stock cover so only you and your passenger feel the difference

Similar to Harley-Davidson’s technique of improving upon their motorcycles without interrupting the classic American V-Twin look, K&N^® RK Series performance air cleaner assemblies will provide upgraded performance without disturbing a bike’s heritage. K&N accomplishes this task by replacing the enclosed air cleaner assembly with an open element washable/reusable high-flow K&N air filter, and bolted-in velocity stack, mounted to a black powder coated aluminum backing plate.

The custom K&N backing plate included with 2013-2015 Softail air cleaner RK-3942 does more than provide a solid mounting surface as it incorporates an integrated crankcase breather system for a trick look that keeps crankcase blow by where it belongs. The entire K&N RK Series Performance air cleaner for 2013-2015 Harley-Davidson Softail models, including the Breakout, Deluxe, Fat Boy, and Heritage remains hidden behind the factory Harley air cleaner cover to ensure only rider and passenger can feel the difference.

K&N high-flow air filters for Harley-Davidson models are handmade in the U.S.A at K&N’s manufacturing facilities in Riverside, California

K&N high-flow RK Series Air Cleaner RK-3942 for 2013-2015 Harley-Davidson Softail models is designed, and tested, to ensure that it will provide a guaranteed increase in horsepower and torque. When installed on a 2014 Harley-Davidson Softail Deluxe 103, K&N RK-3942 was dyno tested and shown to provide an estimated increase of 9.32 horsepower at 4,803 RPM. Equally impressive is the estimated additional 8.71 lb-ft of torque that was seen at a low 2,487 RPM. Increases in both horsepower and torque were witnessed across the entire RPM range. No additional modifications, including fuel injection tuning, were necessary to see increased performance.

K&N washable/reusable high-flow air filters for Harley-Davidson models are handmade in the U.S.A at K&N’s manufacturing facilities in Riverside, California. K&N air filters and K&N air intake systems are designed to last for years to come and are backed by a 10-year/million mile limited warranty. K&N air intake systems, including RK Series Air Cleaner assemblies for Harley-Davidson models, come complete with all necessary installation hardware. Step by step installation instructions with photos and a dyno sheet showing an increase in performance are packed in the box with each and every RK-3942 air cleaner for 2013-2015 Harley Softail models.

K&N performance air cleaner RK-3942 is designed to improve the performance of the following Harley-Davidson Softail models:

When installed on a 2014 Harley-Davidson Softail Deluxe TC103, K&N RK-3942 was dyno tested and shown to provide an estimated increase of 9.32 horsepower & 8.71 lb-ft of torque

2015 Harley Davidson FXSB Breakout 103 CI
2015 Harley Davidson FLSTN Softail Deluxe 103 CI
2015 Harley Davidson FLSTFB Softail Fat Boy LO 103 CI
2015 Harley Davidson FLSTF Fat Boy 103 CI
2015 Harley Davidson FLSTC Heritage Softail Classic 103 CI
2014 Harley Davidson FXSBSE CVO Breakout 103 CI
2014 Harley Davidson FXSB Breakout 103 CI
2014 Harley Davidson FLSTN Softail Deluxe 103 CI
2014 Harley Davidson FLSTFB Softail Fat Boy LO 103 CI
2014 Harley Davidson FLSTF Fat Boy 103 CI
2014 Harley Davidson FLSTC Heritage Softail Classic 103 CI
2013 Harley Davidson FXSBSE CVO Breakout 110 CI
2013 Harley Davidson FXSB Breakout 110 CI
2013 Harley Davidson FLSTN Softail Deluxe 103 CI
2013 Harley Davidson FLSTFB Softail Fat Boy LO 103 CI
2013 Harley Davidson FLSTF Fat Boy 103 CI
2013 Harley Davidson FLSTC Heritage Softail Classic 103 CI

Additional Harley-Davidson upgrades, such as Harley-Davidson replacement air filters, or Harley-Davidson Wrench-Off oil filters can be found using the Search By Vehicle tool. To find an authorized K&N dealer near you, use the Search for K&N Dealer lookup tool.