My Thoughts on Air Filters

Ok, it's not really a modification but I am replacing my K&N. I do not want to run a KN filter anymore, even with an outerware and/or prefilter. The thing just lets in too much dirt and sand. I called up UNI to inquire about having a custon filter made because their catalog doesn't list the size I need. No problem-o, they said. The nice UPS man brought me a package today with 2 pretty new filters, just the size I needed. Just as much filtering as the KN and UNI's are proven to stop the dirt. I only have to figure out an end stud like the KN had or make a different mount for it.

K&N on the left, custom UNI on the right

Easy to remove outer layer

My intake system

"Why K&N Filters Suck"

  After running a large KN filter for a while, I have noticed a lot of fine sand and dirt getting into my motor. The pistons always had the telltale signs of dirt by the small scratches on the sides. I always smear some grease on the inside of the carb boot to catch anything that might be getting by. I usually found more sand in the grease than is ever acceptable. I have run the KN with a foam UNI outerware that stops most of the dirt but it is just that, an outerware, or prefilter. Tried it with the nylon style outerwares with the same result. KN claims their filters flow so much better than anything else out there but they fail to mention that they filter the least amount of dirt. Even with proper oiling and frequent cleanings, the KN lets dirt through. Here is the test anyone with a KN filter should try out: clean the filter by their directions and then clean/wash it again for good measure. Allow it to dry(don't use compressed air to dry them!)overnight. Find a nice clean dark counter surface and tap the filter lightly down onto the counter. Slowly lift the filter up and look for the nice circle of motor destroying grit from the inside of the filter. See the pic for an example, this filter was thoroughly washed 3 times and has had this demonstration done to it several times, still drops sand out...

So, if you have a KN filter, think about all the sand and dust you drive through every time you ride. How much do you think is passing into your delicate motor? KN likes to hype up their product and spend a ton of cash on advertising but sells an inferior product. A foam filter like the stock one, UNI, Twin air, Moose, etc... might flow slightly less air through on a test bench but what really counts is how much dirt is really filtered...

These are air FILTERS after all....

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