Question about Prefilters

[vaget22]

So I have a K&N filter with the K&N prefilter and I found a couple small holes in it. I'm going to replace the prefilter and I'm looking at either the original K&N or the Outerwears. Anybody try either and have a preference? Just wondering if one is better than the other.

[CarGuy7a]

I ran the outerwears pre filter on my K&N for a while but it sits on the shelf now.

The problem is if you ride in a really really dusty area, the outer wears does nothing and all that dust will still cake up your K&N and chances are some of that dirt will still get through the K&N and into the motor.

What I did to fix it was I took my old unused stock filter. I cut the outer yellow foam layer off. It fits perfectly over the K&N. Get some Klotz foam filter oil and oil it up and put it on the K&N and you'll have a foam outer filter.

Really the whole theory behind the Outerwears pre filters is for mud clumps so it won't pack your main filter up. But that is also what the air box is for.

[vaget22]

I don't know, I may just go with a UNI foam filter. There is a lot of dust where I ride.

[CarGuy7a]

I was just giving you an idea of what I did. There's really no need to get rid of the K&N they are good filters.

Usually on everything I run K&N's on I run a foam outer especially if I'm offroading. I just made my foam outer out of my old stock filter since it wasn't being used. It was a cheap mod I did that does work.

Plus the foam outer will catch pretty much all of the dust. That way when it comes to filter washing time, you can just wash the foam outer 2 or 3 times to 1 wash of the K&N.

[bkelley]

There are also foam prefilters. Kind of a strange idea to me, but it might work out well. Claims to give you the performance of a paper filter with the protection of a foam filter.

[guenther]

I have a K&N with an Outerwears prefilter and Outerwears lid cover. I always cleaned and treated everything with the correct products and there was still a film of dust on the inside of the intake tube. I got a Uni a month ago or so and no film at all and no difference in power that I can tell.

[NacsMXer]

Originally posted by vaget22
I don't know, I may just go with a UNI foam filter. There is a lot of dust where I ride.

You would be smart to switch over to foam if you ride in a lot of dust ;)

K&N's are far from the best filter for riding in heavy dust. Leave them to the street (in your car), dunes/sandy areas, and drag racing applications. For pretty much everything else, foam filters better....don't care what anyone says about that :scary: