I got this from an advertisement from Amsoil. Now, this is talkin about an air filter for a car or truck, but I was wondering if it would be the same for a quad, and what yall think of it.
"A 5 x 5 inch. section of a freshly oiled K&N filter is placed on the mounting plate
and secured. ASTM (American Society of Testing Materials) Standardized Air
Filter Testing Dust is sprinkled on the top of the filter section and the machine is
turned on for about 20 seconds. The filter section is removed and the oiled foam
inspected. In absolutely every case of a K&N test, the oiled foam is
extremely gritty and full of test dust particles as is the inside of the PVC
tube."

Hmmm... I have one on my 250R with a drilled airbox lid and it gets really dusty during the summer and I haven't had a problem, I even forgot to wash it after 1 1/2 weeks of riding daily and it still didn't let dirt in, but the outside was caked with oil/dust, so it obviously is working. Maybe it is different for cars/trucks than quads.

damn, I sure hope K&N's for cars are good, I have one in my car!!

if you get one for your quad get an outerwear.

Outterwear is a good idea, but most important, keep it clean and oiled, and check for rips all the time.

Well I don't have one but I was just curious. The way the airbox is set up on my Dale, I don't see how air even gets to the air filter. I mean I can see how but it looks very restrictive.

I have been using the K&N for twenty years, and not untill others started making oil filters did I start hiering about how they were letting far to much dust through.
I pulled the one on my quad and bike, sprayed a little armorall in the air box, put it back together and went riding.
When we were done for the day we inspected the air boxxes, absolutely clean.
I have noticed when in water you will find muddy water type residue in the air box, but this is with any filter.
I also found the worst filters out thier are the stock ones.
I have nothing against any filter, just K&N has been very good to me.

I also didn't have any problems with the one on my old 300ex, but I only had it on there for about a month before I sold it. It also had the outerwear cover. I was just wondering because I'm plannin on getting one sometime for my Dale. I realize that this seems like a post against K&N, but to everyone that is lookin at buying one, it doesn't seem like anyone has had any problems so don't let this scare you away.

I had problems with my well-maintained K&N Filter on my Recon letting dirt past. It was alway's sealed good, but I frequently rode in very dusty conditions, and sometimes when I'd take it off to clean, i'd see dust on the intake manifold, meaning the filtered air was still dirty. I have since put new piston and rings in, switched to UNI filters, and no-longer have a dust problem.