what is the best filter as far as horsepower gain? Or does it make a difference which brand?

Jera '00 400ex

 

I've had good luck with UNI filters, but a lot of people use K&N filters. You probably won't gain any power since Honda's come stock with foam filters.

 

Is it worth the investment? What are the benefits and advantages?

Jera '00 400ex

 

I used a UNI filter and upped my main jet two sizes.

It makes a difference. Not much, but the UNI is a better filter and I get more out of the machine.

RM

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99 400EX 95 Scrambler 400 85 LT250R

 

Definately go with a foam filter if you want to upgrade your stocker. K&N filters will flow the most air, but at the sacrifice of passing the most fine dirt particles (dust). UNI makes a great aftermarket filter for the 400EX. It's a dual element filter meaning it has a coarse outer foam for larger particles, and a fine inner element for dust particles. It also comes with an inner support cage that retains the filter's shape and gives you something to tighten against when clamping it into the airbox. UNI's part number is NU-4126ST. The price is about $25-$30.

Lightninn

 

Lightninn, the K&N filters do not pass more air than UNI filters do you know.

 

I have to back Lightninn up on the K&N issue. It's fairly common knowledge that K&N's pass more dust. I used to race exclusively with K&N's on my old 250x until someone warned me against it. Unfortunately, I had already raced several very dusty courses and my ride was already smoking like a freight train.

If you need it from a more authoritative source, check out CT Racing's comments at, http://www.ctracing.com/air.htm.

Regards,

Dennis

 

many experienced riders run two different types of filters for different conditions; The K&N for sand and a foam filter for finer, more dusty conditions. Foam does filter more of the finer particles. I see that many riders are using filters unsuitable for their riding conditions, ostensibly to gain more air flow, but at the expense of greater engine wear. I run a Pro Design Pro Flow air box kit on my Warrior. It comes with two separate foam filters, one of which fits over the other which is less dense and give you the maximum filtration possible for severe dusty conditions. It mounts with two hose clamps, one holds the inner support cage to the filter and the other one holds the unit to the air intake...no leakage. You possibly wouldn't need the entire adaptor kit like the Yamahas do for their pitiful airbox design. Just the filter is also available.

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THE AZ HARD PACKER, calmiller@kachina.net

save the public land FOR you, not FROM you..join the Blue Ribbon Coalition online @ www.sharetrails.org

 

Will a K&N be alright for woods riding? I don't do a lot of racing where i will be eating a lot of dust following someone. because there behind me! no just some humor
the reason i ask is because the honda dealership swears by the K&N high flow filter and that is all they carry?

Thanks for all your help!!!!!!

Jera '00 400ex

 

I've never owned a K&N filter, but I use UNI filters all the time. I personally have never seen a UNI filter carried by a dealer. I've seen many K&N filters at dealerships, but I just don't know if they're worth the extra money over the UNIs. I usually get them out of Dennis Kirk, who ships them in like 2 days, depending on where you live. However, a K&N should work fine in the woods, as there are usually leaves, sticks, and other things that make the conditions less dusty.