TheSamba.com :: View topic - Which brand air filter for dual IDFs... K&N or CB?

Mon Oct 20, 2008 9:08 am

Got a question about air filters. Which are better, K&N or CB? I got a set of CB filters that came with my carbs & CB bases and they seem to let a lot of dirt thru them. I also wrap them with a UNI foam pre-filter. Would real K&N filters be any better?

My bug gets a bit dirty.

Mon Oct 20, 2008 11:23 am

paper or better yet an oil bath, the tricky part is getting it hooked up to the carbs.

Anton

Mon Oct 20, 2008 4:01 pm

You need an UMP air filter:

http://www.uniquemetalproducts.com/catalog.htm

Mon Oct 20, 2008 5:53 pm

markhuebbe wrote: I got a set of CB filters that came with my carbs & CB bases and they seem to let a lot of dirt thru them. I also wrap them with a UNI foam pre-filter. Would real K&N filters be any better?
I found out the hard way that genuine K&N 4-1/2" by 7" oval filters will NOT fit the CB Performance 4-1/4" x 7" oval air cleaner bases.

Their ad copy is incorrect. It specifies the CB air filters as 4-1/2"x 7", when in fact they are 4-1/4" x 7". I Notified CB Performance of this error over 3 months ago and they still have not corrected it.
http://www.cbperformance.com/catalog.asp?ProductID=509

The other potential problem is that the mold sprues on the CB Performance air cleaner bases have not been ground flat and can keep the air filters from seating properly. The air cleaner bases need finish work before you use them.

I hear a lot of people complain that K&N air filters let sand in. But I wonder how much of this is the filter not seating properly on a poorly made air cleaner base.

Scott Novak

Mon Oct 20, 2008 10:02 pm

To staight out answer your question, K & N. The CB filters pass a lot of dirt.

However RIS is correct, you need a UMP unit if you want to keep the sand and silt out of your engine, the K & N's will not get the job done for you, period. Sorry there is not other way around it.

Tue Oct 21, 2008 6:47 am

Do you think adding an oiled layer of UNI green foam in addition to my red uni pre-cleaner would help any? I don't see why I need some huge air canister when Baja trucks run Uni filters.

Tue Oct 21, 2008 7:17 am

Scott Novak wrote: markhuebbe wrote: I got a set of CB filters that came with my carbs & CB bases and they seem to let a lot of dirt thru them. I also wrap them with a UNI foam pre-filter. Would real K&N filters be any better?
I found out the hard way that genuine K&N 4-1/2" by 7" oval filters will NOT fit the CB Performance 4-1/4" x 7" oval air cleaner bases.

Their ad copy is incorrect. It specifies the CB air filters as 4-1/2"x 7", when in fact they are 4-1/4" x 7". I Notified CB Performance of this error over 3 months ago and they still have not corrected it.
http://www.cbperformance.com/catalog.asp?ProductID=509

The other potential problem is that the mold sprues on the CB Performance air cleaner bases have not been ground flat and can keep the air filters from seating properly. The air cleaner bases need finish work before you use them.

I hear a lot of people complain that K&N air filters let sand in. But I wonder how much of this is the filter not seating properly on a poorly made air cleaner base.

Scott Novak

I just installed K&N E-3341 filters on my CB bases. Outside dimensions are 7"X4.5"X3.25" Fit like a glove!!

Tue Oct 21, 2008 7:27 am

Actually yes you can add the foam wrapper to the elements. It's not the best, but it can work if you pay attention to detail and clean them often.
Here is how we set up filters like you saw for Baja.

-K & N element, oiled, and with greased seal lips.

-"Outerwear:" wrapper, no oil

-Foam Uni filter wrapper, lightly oil on the inside only. No oil on the outside, that would attract silt and you don't want that.

Grease most any motorcycle shop has this stuff-
http://www.revzilla.com/product/bel-ray-waterproof-grease

Outerwear- http://www.cbperformance.com/catalog.asp?ProductID=558

Foam wrapper- http://www.cbperformance.com/catalog.asp?ProductID=1391

I'm not sure what Scott is talking about, I have never had a problem installing K & N filters on CB bases, and I have installed a ton of air filters in my days.

Tue Oct 21, 2008 7:36 am

SRP1 wrote: To staight out answer your question, K & N. The CB filters pass a lot of dirt.

CB's pleated K&N version or their FilStar version?

Tue Oct 21, 2008 7:42 am

Pleated. I assumed that's what he meant when comparing K & N to CB, that's the only comparable filters between the two companies.

Tue Oct 21, 2008 7:48 am

OK thanks guys.

Tue Oct 21, 2008 10:06 am

There's always these...

http://www.aircooled.net/new-bin/viewproductdetail.php?keyword2=FSK0046&cartid=1016200835157171

Tue Oct 21, 2008 1:23 pm

jign4bass wrote: I just installed K&N E-3341 filters on my CB bases. Outside dimensions are 7"X4.5"X3.25" Fit like a glove!!
I would strongly suggest that you take a much closer look at the fit of the K&N 3341 filters on the CB filter bases.

I've got a a pair of K&N 3341 air filters and the CB intake manifold bases distorted the K&N Filters to the point that they were not going to seal correctly. This distortion I saw was exactly what was going to allow sand to infiltrate and require the use of heavy grease or other sealers to keep the sand out. (CB P/N 6480, Cross Bar Linkage for Straight Manifolds with air cleaner bases)

I dumped the air linkage and and air cleaner kit and made my own air cleaner bases.

Scott Novak