K&N was founded in 1969 by Ken Johnson and Norm McDonald (pictured) and today serves the needs of powersports, automotive, marine, industrial and military markets all over the world.

t’s just an air filter, so how complicated can it be? Well, if it’s a K&N High Flow Air Filter you’re talking about it can be pretty sophisticated indeed. K&N Engineering has grown to become the world leader in performance filter technology, and it all started in 1969 when two desert racing buddies, Ken Johnson and Norm McDonald (the “K” and “N” of the company’s name), got the idea of how to get more filtration area out of their motorcycle’s air filters while offering increased airflow. They ended up with significant performance gains while still filtering the airflow in that harsh off-road competition environment. Today K&N has those High Flow Air Filters for more than just desert racers; the company serves the needs of the entire powersports, automotive, marine, industrial, and military markets the world over. Harley-Davidson’s included. A K&N air filter is one of the first additions many Harley riders make.
     K&N’s High Flow Air Filter is a unique piece. It’s completely different in both form and function from a foam- or paper style filter. A K&N filter uses four layers of accordion-pleated cotton gauze as the filter medium, sandwiching it between two layers of epoxy coated aluminum wire mesh. This combination not only does a vastly superior job of filtering out dirt and dust, it greatly increases the amount of airflow over a standard paper air filter on a square-inch by square-inch basis. K&N uses lots of that cotton gauze, too; this company is the second largest consumer of surgical cotton gauze in the United States, second only to Johnson & Johnson.
     Most K&N High Flow Air Filters are designed, tested and manufactured right in Riverside, California, while a small percentage are developed in the UK where K&N has a complete design, testing and manufacturing facility. It’s a hands-on manufacturing process, too, albeit significantly streamlined since the days of individually cutting each filter by first freezing the formed accordion pleats in a block of ice and then trimming the filters to size on a bandsaw. Even so, K&N still employs a sizeable workforce that hand-counts each pleat, cuts the filters to length (modern manufacturing techniques have replaced the ice blocks and bandsaws) and joins the ends of the pleats with an aluminum binder clip. Those formed filter elements are then set into heated molds where the urethane or Plastisol tops and bottoms are permanently attached, and after removal from the curing ovens each filter is hand-trimmed to remove any flash before it goes through a final inspection and into the oiling process. A computerized turntable apparatus applies the correct amount of specially formulated filter oil to the pleated gauze giving the filter its signature K&N red color, and while it might look like an insufficient amount is applied, the oil quickly wicks out to entirely cover the gauze. That’s something to keep in mind during subsequent cleanings and re-oilings. While a K&N High Flow air filter is completely serviceable and will last the lifetime of the motorcycle, over-oiling is definitely not recommended. Besides causing an unnecessary mess it can lead to tuning problems. A little bit of filter oil goes a long way.
     And speaking of service, don’t clean that K&N filter until it really needs it. Unlike a paper or foam filter a K&N actually becomes more efficient as it get dirtier, to a point. A rule of thumb is that when the aluminum mesh is no longer easily distinguishable from the pleated cotton, it’s time for a cleaning and re-oiling.
     Not as simple as you might have thought, is it? Call your Drag rep today for more information.