K&N Air Filters...

[Geolander]

I just recently bought a CRF450X

It had a K&N air filter installed when I bought it.

I have heard that K&N filters are kinda garbage, and let it some pretty large particulates. Is this true?

Although I did just read on their warranties page on their site;

"Million Mile Limited Warranty"

....as long as you don't ride an off highway vehicle on the dirt with it.

"Yeah, we know we made it for your dirt bike."

"No, sir.. You can't take your dirt bike off road with that filter, it'll void the warranty."

WTF?

Why would someone spend $100 on this piece of garbage for trail riding?

I think I already know my answer.

Back to Twin Air's

[Geolander]

What about a pre-filter for the K&N?

[Rockcat]

Asking about K&N is a little like asking about oil...

I had a K&N on my old XR400 that I put thousands of offroad racing and trail riding miles. No problems from the filter, though I broke lots of other things. YMMV

I never used a pre filter.

[The Dogger]

Originally Posted by Rockcat

Asking about K&N is a little like asking about oil...

I had a K&N on my old XR400 that I put thousands of offroad racing and trail riding miles. No problems from the filter, though I broke lots of other things. YMMV

I never used a pre filter.

Did you use the filter oil ? The instructions say something like " spray until oil starts to wick " . What does that mean ?

Cheers

[joexr]

Originally Posted by The Dogger

Did you use the filter oil ? The instructions say something like " spray until oil starts to wick " . What does that mean ?

Cheers

Wick means the oil being absorbed thru the fibers. It'll spread itself. I've used K&Ns for over 35 years. Never had a problem with them on or off road.

[The Dogger]

Originally Posted by joexr

Wick means the oil being absorbed thru the fibers. It'll spread itself. I've used K&Ns for over 35 years. Never had a problem with them on or off road.

Ah , Ok thanks. Couldn't get an image of candles out of my head

Cheers

[Rockcat]

Originally Posted by The Dogger

Did you use the filter oil ? The instructions say something like " spray until oil starts to wick " . What does that mean ?

Cheers

You should see no white in the pleats after application of the oil.

[innathyzit]

Kand N is the only filter I have that will completely block up to the point that the engine stops running. Foam filter keeps on going.

which one is filtering better?

[joexr]

Originally Posted by innathyzit

Kand N is the only filter I have that will completely block up to the point that the engine stops running. Foam filter keeps on going.

which one is filtering better?

I've had opposite experiences. Had caked up K&Ns not clog and foam clog to the point of bike no longer running.

[Geolander]

Man, sounds like a six of one and a half dozen of the other to be honest.

I guess I'll keep it oiled liberally and clean it often. Check my carb from time to time for dirt, keep an eye on the main jet...

I mean, the PO did invest $100 dollars into it. I'll see what's up.

I'm pretty religious about K&N filters on every single vehicle I've ever owned.

A complete cold air system on the cars I build up at all.

Don't they have some gnarly off road racing pedigree?

Was the person freaking me out about K&N filters just misinformed?

[racermx66]

I have K&Ns in my bike and truck and never had a problem. I clean them more than the 50,000 miles they said it could go. As long as you keep the filters clean it shouldn't be a problem. I've had Uni and Twin Air filters that developed tears along the seams.

[NJ-Brett]

I read something on the internet (so it must be true) about a heavy equipment company switching to K+N filters since they were spending lots of money on paper filters for all the big equipment, but they found the K+N filters passed fine dust into the intakes.

If a filter flows more air for the same size, it has to filter less.

Try it, just check that the air after the filter is clean.
If you ride on a very dusty day and the inside is still spotless, its good.
If the intake boot has any coating of fine dust, toss it.

They would be ok on the street I guess, not much dust there...

Paper filters are amazing though, they will pass a lot of clean air even when packed with dirt.

I like the twin air filters for the dirt though.

[Stretch67]

I used to have K & N's on nearly all my stuff, before I knew better.

One day when I had the filter out of my F-350, I held it up to the sun on a whim. There were tiny pinholes all along the folds of the pleats. I held the filter right up close to my eyes and I could read my license plate through the filter.

If you can read through your air filter, it ain't keeping the fine particulates out of your intake..

I got rid of all my K & N's after that. Wix paper filters with the foam pre-filter for the Jeep and truck, Uni's for the bikes.

[Sparrowhawk]

Originally Posted by Stretch67

I held the filter right up close to my eyes and I could read my license plate through the filter.

If you can read through your air filter, it ain't keeping the fine particulates out of your intake..

This! You really can see the holes in a K&N. K&N filters flow more air. K&N filters pass more fine particles. It's only whether that has a negative effect on the longevity of an engine that's at question.

Sent from my SCH-I535 using Tapatalk 2

[Off the grid]

I think through the years K&N has let their quality slip. I'm partial to No-toil foam myself for offroad, but a filter thread is a minefield just like an oil thread.

Find one that works for you. Personal experience is your best guide.