he wait is over. K&N’s “RK Series” Filter/Backing Plate-Breather Kits, the kits that have transformed the performance of untold numbers of ‘99 and later Twin Cam Harleys, are now available for the Sportsters. Specially designed and tuned RK Series packages are ready for both the 883 and 1200 XLs, brand-new filter and backing plate combinations with the same K&N high-flow performance that the Twin Cams have enjoyed since the RK’s debut. The performance gain here is impressive, too. Preliminary dyno testing with a 1200cc Sportster with K&N’s new RK Series Filter Kit netted an 11-horsepower jump, and that’s just the beginning. The RK Series Filter Kits are easy to install, they work great and now they’re available for the Sportsters. It’s Part No. 1010-0322.


All of K&N’s products go through extensive dyno and road testing to ensure that the customer receives the best possible results.

     Like the original RK Series Filter Kits from K&N, the new Sportster kit retains the stock Harley-Davidson filter cover. What’s behind that OE cover, however, is anything but stock. Of course this oversized, custom intake assembly was developed and based around an original K&N High-Flow Air Filter and everything included in the kit–that filter, the new backing plate and the velocity stack–been designed to optimize air-flow and significantly increase Sportster performance. That High-Flow Filter, as in previous RK Kits, mounts to a brand-new backing plate designed just for the job. A neatly crafted piece of billet aluminum, it’s powder coated for good looks and durability, it features designed-in internal breathers for a clean installation and mist-free operation and there’s a built-in and dyno-tuned velocity stack to speed up and smooth out the airflow. All this fits right behind that OE-stock air cleaner cover. Outwardly the Sportster keeps its factory appearance.
     K&N’s RK Series Filter Kits are all-in-one naturals. Everything that’s needed comes wrapped up in one, neat performance oriented package. One of the first things most Harley riders do is put in a K&N High-Flow Air Filter. Matching that K&N filter with a free-flow backing plate ups the performance gain exponentially. A stock Harley, Twin Cam or Sportster, is pretty restricted on the intake side. That simple filter/backing plate swap reaps huge benefits. Until now, however, this meant combining that K&N High-Flow Filter with a backing plate from some other supplier and maybe a breather set from someone else. The RK Series Kits eliminate all that shopping and running around. Also gone is the uncertainty of wondering if one part will really work with and complement all the others. By coupling that free-flowing K&N High-Flow Air Filter element with a less-restrictive backing plate and velocity stack that’s been designed and developed by the same people supplying the filter itself you’re guaranteed to have a V-twin breathing to its full potential. In no time at all, and using only simple hand-tools, a bike becomes more responsive, lots crisper and lots more fun to ride.


At the heart of the RK Kit is an original K&N High Flow Air Filter; the same one riders have relied on for years.

     And with the RK Series Filter Kits all this is easier than ever. Everything’s right there in one box and it’s all K&N. Each part is made to fit and work with every other part supplied. There are no surprises, no mis-matches, no mistakes and no worries. The backing plate and its velocity stack are designed to be a perfect match to that High-Flow filter element, and the breathers that K&N has designed are built right into the backing plate completely eliminating the need for any unsightly, and leaky, external add-ons. If there’s a company that knows how to maximize airflow it’s K&N. All that experience, decades worth, is right here in the RK Series Filter Kit. And now it’s available for the Sportsters.


The RK Series Filter Kits come with a built-in and dyno-tuned velocity stack.

     The RK Series Filter Kits are in the warehouses now. The applications are for all 2004 and later Harley-Davidson Sportsters, both the 883s and the 1200s. Drag Specialties has them. Don’t forget about the RK Series Kits for those Twin Cams, either, the originals (Part No: 1011-0520 & 1010-0273). Either way, Sportster or TC, the result is vastly improved breathing and filtration, increased performance, enhanced rideability and a good chance for improved economy. And it all comes in one box and from one place–K&N Filters.