As many Blaster riders do, I run a UNI foam air filter. Why? Its hard to find another brand of filter which does the job so effectively at a reasonable cost. At around $ 35.00 for a round one (I have a CFM airbox, but you can buy UNI filters for a stock airbox), they are priced reasonably and sold almost everywhere ATV/motorcycle parts are sold.
To make a UNI filter work properly, you have to oil it. Thoroughly. Inside and out. Except for being a somewhat messy job, its easy to do with just a pair of gloves and some rags. You can't use regular motor oil on a UNI filter because the oil will just run right off, but you don't have to go out and spend $ 10.00 or more on a quart of special "foam filter oil", either. All you need is an oil with tack additives to make it sticky. You can save some $$ and just stop by Lowe's or Walmart to pick up a bottle of chainsaw bar and chain oil. You can buy a gallon or more of saw bar oil for what a quart of the specialty stuff costs. Im sure some people will wonder how well bar oil really works, but coming from a career chain saw and small engine mechanic, trust me when I say this stuff is beyond sticky and hard to clean up if it happens to leak or spill. My. 02
Bottom line is, save a little $$ over a K&N filter (which will leak dirt if not meticulously washed and oiled), and put a UNI filter on your Blaster. Your engine will run better and longer. Plus, when you get a UNI filter dirty, just soap it up thoroughly in the sink, wash and rinse well (repeat if needed), let it dry, re-oil, and reinstall. Quick and easy. If you've got an especially nasty filter, you can get some foam filter cleaner, which will strip oil/ dirt off the filter better than regular dish soap.
To make a UNI filter work properly, you have to oil it. Thoroughly. Inside and out. Except for being a somewhat messy job, its easy to do with just a pair of gloves and some rags. You can't use regular motor oil on a UNI filter because the oil will just run right off, but you don't have to go out and spend $ 10.00 or more on a quart of special "foam filter oil", either. All you need is an oil with tack additives to make it sticky. You can save some $$ and just stop by Lowe's or Walmart to pick up a bottle of chainsaw bar and chain oil. You can buy a gallon or more of saw bar oil for what a quart of the specialty stuff costs. Im sure some people will wonder how well bar oil really works, but coming from a career chain saw and small engine mechanic, trust me when I say this stuff is beyond sticky and hard to clean up if it happens to leak or spill. My. 02
Bottom line is, save a little $$ over a K&N filter (which will leak dirt if not meticulously washed and oiled), and put a UNI filter on your Blaster. Your engine will run better and longer. Plus, when you get a UNI filter dirty, just soap it up thoroughly in the sink, wash and rinse well (repeat if needed), let it dry, re-oil, and reinstall. Quick and easy. If you've got an especially nasty filter, you can get some foam filter cleaner, which will strip oil/ dirt off the filter better than regular dish soap.