XR 400 Air Filter

OK guys, this might be a stupid question so bear with me. I have a K&N air filter on my 400 that I want to get rid of due to the negative thing I have read about them on this board. It sounds like most of you like the UNI filters. Does a UNI flow better than the stock foam filter? Will the decrease in air flow from the K&N to a foam filter effect the way my bike runs (jetting)? Or is the difference in airflow nominal. I remember when I installed the K&N I was amazed at how much more air it moved over the stocker. Any thoughts would be appreciated. Thanks!

:thumbsup:

Good call to ditch the K&N I used to use them exclusively. Then one day I bought one for my new XR650R rode it once and cleaned the filter and was floored by the amount of fine dust that passed through the brand new K&N. I got rid of it and went UNI and never looked back. The UNI breathes about the same amount of air that the K&N does and I did not have to re-jet. I cannot speak for the stocker as I have always chunked the stocker as soon as the bikes get home, I just dont like all of that restrictive looking screen in them.

If you use the Uni screen (one less layer of screen-actually two cuz stoker has folded screen between frame) along with the Uni filter it will be close to the K&N.

No need to rejet unless the other Gordon mods are completed.

Thanks guys, do the UNI filters come pre-oiled?

They do not come pre-oiled. The stock filter works the same as a UNI if you cut out the anti-backfire screen which is a PITA!

Thanks, I think I'll spring for the UNI. What oil do you recommend? No Toil?

I started using no-toil on my UNI and I've never gone back. It works well and you can toss the cleaning solution in your yard with no polution worries. I believe No-Toil also came out rather well in a "filter oil" shootout one the dirt bike mag's did recently.

Thanks Kickin!! I'm on my way to the TT store right now. :thumbsup:

I can't say enough about the easy and clean to use No Toil products. I wash my Uni's in the kitchen sink. And they last so much longer too. No chemicals to dump or ruin the materials. :thumbsup:

No toil destroyed my brand new, stock, expensive, Suzuki dr650 filter...no joke. It came off my bike one time and went straight into the garbage.

Just stretch a pair of old underpants over the wire cage.

Underpants are very effective in filtering solids while readily allowing gasses to pass through, and although less effective at filtering liquids in high quantities, underpants offer more absorbtion than do stupid oil-soaked bits of foam. I have NEVER heard of anyone ever using oil-soaked foam underpants and people have been farting for a lot longer than motorcycles have been around.

Meat (oops do farts have lumps?) bomb.....

Just stretch a pair of old underpants over the wire cage.

Underpants are very effective in filtering solids while readily allowing gasses to pass through, and although less effective at filtering liquids in high quantities, underpants offer more absorbtion than do stupid oil-soaked bits of foam. I have NEVER heard of anyone ever using oil-soaked foam underpants and people have been farting for a lot longer than motorcycles have been around.

Meat (oops do farts have lumps?) bomb.....

Probably keep out more than a K&N. I'm a UNI fan and I use the UNI cleaning and oiling stuff also.. :thumbsup::lame:

I was very happy with the Twin Air cage and filters. They fit very well and were quite durable. Just another option you may want to check out...

Just stretch a pair of old underpants over the wire cage.

Underpants are very effective in filtering solids while readily allowing gasses to pass through, and although less effective at filtering liquids in high quantities, underpants offer more absorbtion than do stupid oil-soaked bits of foam. I have NEVER heard of anyone ever using oil-soaked foam underpants and people have been farting for a lot longer than motorcycles have been around.

Meat (oops do farts have lumps?) bomb.....

I say that TT gives Meatbomb his own tech-tip forum. We can all save lots of $$ and start a motocycle revolution! BURN BABY BURN!

K and N's do flow a lot of air.If you carefully read their web site you will note that it talks about superior air flow but never superior filtration.

Several years ago me a buddy were riding in Flagstaff, AZ @7500 ft. altitude. His brand new stock XR 400 would sputter and chug unless you had the throttle wide open and the plug was black. It was Sunday so we couldn't get leaner jets. One of the locals told us to leave the jetting stock but use a K and N. I took my K and N out of my XR250 and put it in his bike. The bike ran great and the plug cleaned right up.

However I will no longer use K and N's . Tried them in my truck and car. When it came time to clean the K and N there was a layer of dust coating the intake track past the filter. For the non noticable gains in horsepower I tossed both K and N's. The risk of shortening the engine life wasn't worth the non noticable performance gains.

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