Air Filter...aftermkt or OEM ?

I was cleaning my air filter the other night and noticed it torn and somewhat crumbling near the front seal and thought I would replace it. I didn't know if I should go with the OEM or aftermarket filter. My local shop was recommending the UNI and said it was much better than the Twin-Air. Was just wondering what the experiences of others have been.


Two-Wheel Thrill!

I have not yet seen any dirt get through the stock filter so it seems to work fine, but I don't like how the coarse filter is so attached to the finer inside filter. It makes it more difficult to get oil on the outside of the inner filter without soaking the whole thing. I've never tried twin-air so I cannot comment on that part.

I got a UNI as a second filter after I got my bike. It seems to be a little better contruction (and it is in two separate pieces). I can't say if it's really any better though. They both seem to do what they are supposed to do and I don't notice any performance difference.

But here's a testimonial. Check out No-Toil filters, cleaner and filter oil. The filter is of good construction and is bonded specifically to resist the effects of the cleaning agent. The cleaning process is the key to this system, though (it works fine on my other filters too). You have to use the No-Toil oil for the cleaner to work. I got real tired of using various degreasers on my filters followed by soap to get the degreaser out. With No-Toil, a quick dunk and a few squeezes in the sink and I've got a squeaky clean filter. The cleaner and residue are safe for the drain. I maintain three bikes and usually prep two or more filters for each bike. I store the extras in plastic bags to keep them from drying out too much before I'm ready to use them.

stock is great. Twin air filters are great. I find uni filters to be a pain in the but. They are like servicing two filters for the price of using one(because they are 2, the 2 stages acually separate to make life more difficult).

Twin Air, No Toil, White Bros. Those are my choices. Have never had any problems with any of them. Uni's are a pain as I could never get them to seal both sections properly.



Life is too short, work hard

Sponsored by Yamaha of Cucamonga, Larry Roeseler's Stroker Fourstroke Speed Equipment and Answer Racing

Here is what i have read.

The standard filter is junk. One, it is too restrictive. Two, the foam seal seems to fall apart on some filters only after a few months. Mine fell apart after one month. Finally, the inner and outer layers (fine and course layers) are not bonded together, so dirt can get trapped in between the two layers and cannot be cleaned out easily, if at all.

Im using a Finafilter o2 rush, and it isn't too bad at all. They claim a perfomance increase due to a larger surface area (it is jaggered on the outside) but i didn't notice much. The inside isn't jaggered, so i don't understand how they claim an increase in air flow due to this, but there is more surface area to trap dirt on the outside.

I personally recommend twin air filters, and if i needed another, thats what i would buy. They seem to be really well engineered and constructed.

Ernie nailed it. Twin Airs are white, so they show the oil better. NoToil is incredible. You have to try it to believe it. You can get 3-4 dirty filters, throw them in the washing machine (when the little lady is not home), and they come out like new. It's the simplest and least polluting way to do it.

I've never heard of "no toil", can you give us the overview?


The No Toil filter itself is very similar to the Twin Air or White Bros. (single stage). The thing that makes the No Toil very nice is the bio degradable oil and cleaner. You can clean it in the kitchen sink or the washer if you are so inclined. Cost is no higher than the above mentioned filters.

I use the garage sink to clean mine as the lovely woman would shoot me if I used the washer!!!



--Life is too short, work hard--

Sponsored by Yamaha of Cucamonga, Larry Roeseler's Stroker Fourstroke Speed Equipment and Answer Racing

What do you guys wash your filters with?

I cant seem to get the old oil out of it and im afraid of using somthing too strong that would damage the foam.

I use twin air filters they are fine


Originally posted by ryan cooper:

What do you guys wash your filters with?

I cant seem to get the old oil out of it and im afraid of using somthing too strong that would damage the foam.

I use twin air filters they are fine


er... umm... NO-TOIL! :)

Try it!

Actually of all the things I tried on regular foam filter oil, diesel fuel followed by strong dishwashing soap worked pretty good and the smell is not too bad.

[This message has been edited by neWRiver (edited September 29, 2001).]

Try using truck wash. Works great for me.

Anybody try the K&N yet? I just found out that they make one for the 426...check it out at

about half way down..Its not cheap..almost 60.00..I also have the UNI..just because my stock filter ripped and that was what the local dealer had in stock. It seems to be of sturdy construction..I kinda like the 2 piece bike isnt any faster with it though.


[This message has been edited by flyinguitars (edited October 01, 2001).]

For years I have used paint thinner to clean filters. It is basically the same as mineral spirits but much cheaper. I keep 2 gallons in a 2 1/2 gal bucket with a snap on lid. You wash the filter out in the bucket, then use warm soapy water. The dirt goes to the bottom of the bucket so the next time you have clean solution again if you are careful not to stir up the bottom. Occasionally I strain the stuff thru an old rag to get the sand out. About twice a year I replace it with 2 new gallons. I have never had a problem with filters breaking down or dirt in my engine. As with any cleaner be careful not to twist the filter when wringing it out, only squeeze.

I just put a No Toil filter in my 426, and it seems to work great (my stocker was crumbling at the seal). I always clean up filters in a dishpan with a strong solution of clean green. It degreases and cleans. I then reoil with UNI oil or K&N oil (red), easy to see. I strain out the excess, and all is good. Carry an extra already oiled in a plastic baggie, just in case. BTW the BK mod is great. I put in a 168 main and the bigger pilot (46). The thing flat rips and no more bog off the bottom. I let a few other riders try it out this weekend and they loved it. They will be bringing their bikes over for the mod soon.


[This message has been edited by Scooter426 (edited October 01, 2001).]

By the way, has anyone tried the K&N 426 filter?

i have always used K&N filters in my car and think that they are the absolute best filters for maximum HP. I really would like one for my bike and would love to feel the difference, but they have a downfall that prohibits me from using one. They allow air to flow too well. Sure, they trap the dust as well as any other filter around but if you hit a deep puddle or need to make a water crossing, they will allow water to flow through them freely. I had my filter hanging down close to the road in my car and drove home on a rainy day. When i arrived home, i had to remove the filter and pour out the accumulated water.

A good example of how well they flow is when the filters are being washed. Water from the tap flows straight through a K&N while its harder for it to flow through a foam type filter.

Can someone please share their own experinces on this issue, because i still want to use one, even if its only on sunny days. i think they are that good.

I would be hesitant to use a K & N filter for dirt riding. DOC is correct about the flow of the filters. If it would allow that much water to pass through, it would also allow dust and sand to flow though it too.

Although the OEM filters are not the best at allowing airflow, there are far superior to a K & N filter in regards to stopping dust and sand from entering your engine. That is why they come from the factory with a foam filter that requires oiling.

This post reminds me of the Fram filter can pay me now or you can pay me later!!!



--Life is too short, work hard--

Sponsored by Yamaha of Cucamonga, Larry Roeseler's Stroker Fourstroke Speed Equipment and Answer Racing

The secret to keeping your airfilter alive is not using harsh chemicals to clean it. I have the original filter from my YZ400 (in addition to two more Twin-airs, and the WR's new filter), and it's still in great shape. I clean it in two stages; Mineral spirits to clean the oil and grease (and most of the dirt), and warm water with dishwash liquid to get the rest of the dirt and mineral spirits out. Then just let it dry, re-oil, and long live your filter!



01' WR426

99' YZ400

87' FZR1000

Uh, like twist the throttle...

I prefer the stock filters. They provide a larger surface area than any of the aftermarket filters. More air = more power!

I have not had any destruction of the stock filters except around the center bolt hole. I wash all of my filters in Kerosene - it cleans perfectly, does not destroy the element. I also have a White Bros that works great with a rubber grommet for the bolt hole. Uni 2 stage filters are a pain in the @$$! Twin Air work, but I prefer the other 2.I also use BelRay Filter oil.

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