Originally Posted By: Jimkobb
This is for a motorcycle.
Nearly all the answers are about cars - don't these guys read, or do they just have to comment no matter what?
I have K&N's on 3 of my bikes. One is because the OE filter is not available (Moto Guzzi Stornello) I use one on my Honda TLR200 trials bike too, this is a performance modification, not because the OE filter is restrictive, but because the flame trap is. Much more throttle response in that slam the throttle open from a standstill to get up a vertical bank, rock, tree etc. Both these filters are from another bike that had carb modifications...different carbs that didn't fit the airbox. Just using what I have in the shed.
I also have a K&N on my BMW R65, this time because it was cheaper than OE. No performance or fuel economy increase, but I didn't expect to see that. It's been on for a couple of years and have monitored dust in the inlet tract - appears pretty clean to me.