Anyone run a K&N air filter on a 04

[doug CRF450]

I am just wondering if anyone is running one, if so how do you like it, how easy is it to get in the air filter box on the bike?

Doug

[MELK-MAN]

i have an 04, and an 08.. i would NEVER run anything but a foam filter soaked with sticky filter oil on a dirt bike. A k&n type filter is asking for trouble.. I actually run a hair net over my filters that i can pull off if they get caked a bit and then the reasonably clean filter is revealed.

[oakhillbiker]

NEVER run anything but a foam filter soaked with sticky filter oil on a dirt bike. A k&n type filter is asking for trouble

?

[MXandSXracer21]

Yep, general consensus around here is that K&N filters suck for dirt bike applications.

[joman2055]

i happen to have one for sale (because i dont want to run it on my bike ? )

i might run one on the street but id still prefer the protection of a foam filter

i also noticed that it doesnt seal very tightly to the base of the air box, i could easily stick my fingers between the filter and the air box, i had to add a few washers to the air filter bolt in order to apply more pressure to create a better seal.

[mikewrf18]

Yep, general consensus around here is that K&N filters suck for dirt bike applications.

Add me to the consensus.

[MELK-MAN]

i happen to have one for sale (because i dont want to run it on my bike ? )

i might run one on the street but id still prefer the protection of a foam filter

i also noticed that it doesnt seal very tightly to the base of the air box, i could easily stick my fingers between the filter and the air box, i had to add a few washers to the air filter bolt in order to apply more pressure to create a better seal.

.. wonder if by definition it could be classified as a "filter" at that point?? LOL ?

[willbilly]

I have K&N's in all of my street vehicles, but as stated above I don't trust them on an mx bike anymore (ran them on bikes back in the 70's.) I did put a Loudmouth on my crf450r. Expensive, but quick and easy to install. There is no way that you will install it without getting it seated properly.

[moto119]

Melk - what kind of hairnet. Just a normal one like you would see at a hospital or cafeteria. Notice any kind of power change? Do you use it to simply to extend the time between air filter changes or perhaps on longer rides or races between multiple motos? I ask only in that I have access to hairnets and have never tried this.

[MELK-MAN]

Melk - what kind of hairnet. Just a normal one like you would see at a hospital or cafeteria. Notice any kind of power change? Do you use it to simply to extend the time between air filter changes or perhaps on longer rides or races between multiple motos? I ask only in that I have access to hairnets and have never tried this.

yup, basic hair net with the thin elastic band. i order them in boxes of 100 for like $6, from an office supply website (office depot maybe?? can't remember..). Yes, i use them as for the woods im not worried about 1/2 or so hp loss, and honestly, i can't see them restricting flow. After a few hours of riding in dust, i can peel it off and tuck a new one on.. yes, it's for the sole purpose of extending intervals between air cleaner changes. I think there is more potential for getting crap in the air boot when changing an air filter, than running one a bit too long (if it's properly installed and properly oiled).

Normally i don't push the bolt through, but had for some reason when i took this pic for someone else awhile back.

Uploaded with ImageShack.us

[DrDuke]

The hairnet idea is awesome. I'm with everyone else, unless your pro then why worry about the minor gains of a K&N, think about protection.

[bushman45]

Yep, general consensus around here is that K&N filters suck for dirt bike applications.

yeah K&N filters suck, oh wait a minute, the motor does that every other stroke. K&N been around a long time, 40 plus years, that's a statement in it's self.

[MED]

I'll chime in since it's Saturday night with no race tomorrow. Way back when (1988!!!), I had the most awesome experience to work at ATK motorcycles in Los Angeles. When we first came out with the 406 two-stroke, the stock filter was a K&N mounted to a 'snorkel' in the high mounted airbox behind the front numberplate. They were sold that way for just over a year and we raced every weekend around So Cal. At that time, Willy Musgrave was the Production Manager and raced every weekend. He would replace his topend after only three; sometimes four weeks (I always thought this was a bit excessive.....) but he was convinced he could feel the bike/engine when the slap got bad enough...... I think sometime in 89 we changed to a dual stage foam Unifilter/oiled. Willy's interval of piston replacement tripled! "The topend stays tight so much longer, it's quite amazing" he'd say. We used them on the four Strokes as well although we'd put a unifilter 'sock' on the outside of the K&N. The K&N would basically just be a 'holder' for the oiled sock. The fourstrokes ran so much less RPM that dirty airfilters were much less of a problem. Anyway, back to the two strokes, that sealed the deal for me. I remember cleaning the K&N's, learning about NOT using an air compressor to blow them dry, oiling them up with the messy spraycan, etc etc etc just so they can pass dust/dirt and ruin engines/cranks/etc. Oiled foam all the way; preferably, dual stage. Hairnets, filter skins both icing on the cake for extended intervals. Good stuff guys MED

[m320]

Wow hate to be the old ball here but I run a K&N on my 07 and its been the best...Ran the stock foam and the twin air and both let dust get through not so with the K&N....Just saying this is my experience with the filter....I run twin air on both my 2-strokes with no problems.....Just thought I would chime in here...

[Vegasdirtrider]

I run K&N air filters in all my dirt bikes, both 2 & 4 strokes. I ride in the desert outside Las Vegas, extremely dusty conditions most of the time. I have never had a problem with K&N air filters not performing.

[PETE24]

Wow hate to be the old ball here but I run a K&N on my 07 and its been the best...Ran the stock foam and the twin air and both let dust get through not so with the K&N....Just saying this is my experience with the filter....I run twin air on both my 2-strokes with no problems.....Just thought I would chime in here...

if your twin air let dirt though then you dont know how to oil a filter!

[m320]

Really!!!! OMG! A Smart A$$.................

[bushman45]

Really!!!! OMG! A Smart A$$.................

went you bring the K&N air filter subject up, they come out of the wood work.