I dont know much about if they are doing anything with the K&N on the SX, but from what I do know about KTM's and dealing with them, I wouldn't run one. Personally I run Twin Air and wouldn't run anything else. K&N filters have been used on my Honda's in the past, but with the SX, and the design of the intake, I would have to say that Twin Air, or foam filter is the way to go.
Just my .02. If you find some info out, let us know.
jay
2009 KTM 450 SX - Race Bike
2009 KTM 450 SX - Practice Bike
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