There's has been a lot of discussion regarding the need for a pre-filter when using a K & N air filter.
I run a K & N on an Eiger 400 4 x 4.
Last week I had the "opportunity" to operate the quad over 125 miles in fine dust so thick I had to slow or stop for safety reasons numerous times.
Upon returning home, I opened the airbox and saw a dust and dirt covered air filter so filthy it was hard to see the pleats.
I removed it, expecting to see some amount of dust in the throat of the airbox where the filter attaches.........and much to my surprise......there was none. No noticeable contamination without a pre-filter.
The use of one is certainly not a bad idea.......but with proper maintainence, not an absolute neccessity.

 

You bring up a good point Hollywood330. K&N makes a great filter; there is know doubt about that. I think that most people that complain about K&N filters are lazy. They oil them up once and go riding. Then when they get packed with dirt they knock them off and don't "really" clean them and re-oil them like they should. Then when their engine gets dusted they complain about junk K&N this and junk K&N that. From your results it sounds like you know how to do it right.

Oil is the life blood of a cotton gauze type filter. If you don't do it right your going to have a mess. I think a pre-filter is a great idea but like Hollywood330 says not a neccessity. A really good idea if you are in competition. You can knock the pre-filter off in about 10 seconds and get 80% of the dirt off, and get back in the race again.

To the people that want a filter: If you don't have the time or energy to do a K&N right then I think you should stay with a paper filter.

 

Yea I just rode in some think think dusty dirt, looked at the K&N through the prefilter and it was spotless!

 

A dirty K&N filters better than a clean one! If you read K&N's literature, they equate it to throwing a rock at a pile of rocks. In a pile, the rock you throw has no way to reach the bottom, because there are so many other rocks below it. But, the problem with a K&N is that the dirt will draw the oil out of the filter and leave you with dry gause.

The one thing that you weren't able to detect in your intake tract is the very little stuff that got through. It's to fine for you to feel, but still way larger than the clearance in your rings. A K&N is pretty much one dimmensional. If something isn't caught on the surface, there isn't much bulk behind it for added insurance.

I ran K&N's WITH OUTERWEARS for years, with no apearent problems. But, I changed filters as soon as the Outerwears got a little dirty........that is, almost every ride. If I couldn't change the filter, I would at least change the Outerwears. Got real tired of that, and went back to UNI foam on everything. I now sleep way better at night!

 

On my 3rd atv with K&N with no problems. I really think it boils down to your riding conditions as to which is best. The K&N is a cotton gauze that WILL break down if it gets wet. If you ride in conditions that require frequent cleaning or if you ride in water or mud, I would use a foam filter. Fo hard-pack and sand, K&N is the way to go.

jmo.

 

Well I was wanting to go with the K&N on my 05 Suzuki Eiger. I do alot of mudding. I'm going to go with a bigger jet. Should I go with the Uni-Filter with foam or K&N, or just stay with stock? Come on guy's I already had my mind made up with the K&N. Should I go with something different with my bigger jet and spark arrester removed. I need air, don't I. Let me know something. Thanks.

 

If you want more air on a ute, you need to redo the snorkel. K&N/Uni may help, but the stock snorkel will still limit air flow.