Not to start a fight....K&N over others

[HondaEXrider22]

OK, I am not looking for which filter better, but which give me the best power. I have the WB airfilter right now and it seems the same as stock. Will I notice any difference from the WB to K&N?

[csimp3]

well, K&N's are not foam filters, they have gauze as their filter, a foam filter will do a better job of actually filtering everything out, a K&N will give you better airflow, but will need to be cleaned out more often, but it is also easier to clean, in my opinion, a K&N with an outerwear is the best way to go, very good airflow, with good protection against sucking something into it

[MO-EX-RIDER]

k&n is a good filter for power. it must be properly oiled and cleaned often...try to stay away from dusty conditions because they do allow fine particles in, this is where a foam filter is a better choice

[250exkid]

K&N = more air flow witch = more power but if you go with k&N get a precharger

[450RGNCC]

I remember seeing somewhere that on a dyno the K&N had like 1/2 more horsepower than an aftermarket foam type, but at the same time the foam type had about 1/2 more ft lb of torque. It honestly doesnt matter which filter you use, everyone has their personal favorite, what really matters is that you get rid of the stock metal cage inside of the filter and repalce it with the cage from Pro Design, Sparks, or whoever else makes them.

[northwest Texas]

To answer your question, No. If you can feel the difference then your butt is way too sensitive.

[HondaEXrider22]

Originally posted by 450RGNCC
what really matters is that you get rid of the stock metal cage inside of the filter and repalce it with the cage from Pro Design, Sparks, or whoever else makes them.

Why..? More airflow?

What would happen if I ran without one completly?

[Quadjunkie]

Sorry, not to steal the show. But if you run the outerwear with the K&N how do you clean it, and must it be oiled as well?

[Quadjunkie]

Sorry, not to steal the show. But if you run the outerwear with the K&N how do you clean it, and must it be oiled as well?

Also, does the guaze wear out? When clean mine is a dingy grey color, not reddish at all. How can you tell when they have become ineffective?

[F-16Guy]

Originally posted by HondaEXrider22
Why..? More airflow?

What would happen if I ran without one completly?
The stock filter assembly has a perforated metal frame that the foam is attached to, and it's pretty restrictive. If you replaced the whole filter assembly with an aftermarket one, you should be fine. You can't really run the filter without the internal cage, because the foam will colapse. The aftermarket cages are designed differently, and allow more airflow.

[F-16Guy]

Originally posted by Quadjunkie
Sorry, not to steal the show. But if you run the outerwear with the K&N how do you clean it, and must it be oiled as well?

Also, does the guaze wear out? When clean mine is a dingy grey color, not reddish at all. How can you tell when they have become ineffective?
The Outerwears is a nylon mesh pre-filter; it's just meant to keep out the big stuff. It doesn't require oil, just clean and dry.
You should be using the K&N cleaner and oil, NOT foam filter oil. The K&N oil is what turns the filter red. That is so you can see what you've covered or missed. The critical thing with the gauze-type filter (like K&N) is to spray on the cleaner liberally, let it soak a while, and then flush out the filter from the INSIDE with a high volume, low pressure stream of water, such as a garden hose with an open end. Spraying with a high pressure nozzle will seperate the gauze and allow dirt to pass right through.

[2muchquad]

It honestly doesnt matter which filter you use, everyone has their personal favorite, what really matters is that you get rid of the stock metal cage

It would be hard to tell the difference for the average rider.I do cut out the steel mesh from the stock restrictive cage assembly though.Its a backfire screen but it chokes the motor imo.I have a k&n but i run a regular foam air filter from time to time as well.

[bradley300]

the stock filter on the yfz is the best. the others make more power when brand new, but loose all of it quickly once it gets the slightest bit dirty, the stock filter dosent do this

[bwamos]

On the 300ex.. go with either one. UNI or K&N w/ precharger.

People say that K&N's let too much dirt through.. I say bah.. I've been running K&N's in the missouri trail dust for 9 years without issue. My 330ex build is 6 years old and still running strong w/ full compression and excelent leakdown and I'm not easy on the engine either.. I'm a rev'r not a lugger.

Th emost important part with the K&N is proper maintenance. If you don't do it right you're gonna get hosed. Most people that have problems use the wrong cleaner and dissolve the adhesives that seal the gause to the plastic ends, and improperly oil the filter, or use the wrong filter oil. Or, they try to clean it from the outside in forcing the dirt further in, instead of from the inside out forcing it out.

I have 2 K&N's. 1 clean. The other on the quad. I swap them out after every ride, and clean the other one, let it dry for 24 hours, then oil it, bag it and box it for next time.

Also the OP appears to have a 300ex the filters aren't swappable between the 250x and 300ex. They are model specific. One of the few things that are. The 250x filter won't want to stay in the 300ex airbox flange, it will keep wanting to fall of on you. It's also slightly smaller filter with less surface area.

K&N part# for 300ex: HA-3094 Cylindrical Filter (you need this one)
K&N part# for 250x: HA-2505 Tapered Filter

[04TRX400EX]

Originally posted by csimp3
well, K&N's are not foam filters, they have gauze as their filter, a foam filter will do a better job of actually filtering everything out, a K&N will give you better airflow, but will need to be cleaned out more often, but it is also easier to clean, in my opinion, a K&N with an outerwear is the best way to go, very good airflow, with good protection against sucking something into it

My thoughts exactly. A K&N with an Outerwears is a great setup. Just be sure to keep up on the cleaning.