Scott's stainless steel oil filter for WR450

Wanted to hear from WR owners about this product. Let me hear your thoughts on it if you have used one on past YZF models, how it worked for you, any problems encountered. It is quite expensive at $70. If it lasts like they say it does, cleans easy and filters down to 35 microns, sounds almost too good to be true.

I'm planning to keep this new bike a long time.

I use synthetic motor oils in my road bikes and my WRX with good success. I just wanted to know about using them in this motor. Is it recommended or discouraged?

I run one in every bike that I have owned. This includes dirt, street and road race bikes. The longest history I have on one is the 98 WR400 I owned wich I still see riding around. When you look at the price of the stock filters it does not take long to recoup your investment on the Scotts.

How long will the s/s filter last? I just bought 2 stock paper filiment filters & they cost me $13.25 ea. :)

Is 35 microns better than stock? If so, what do the stock filters go down to in microns?

Sorry to reply after my reply. :)

Here is my take on this subject. First, Yamaha has been using metal screen filters for years. I still have a 1986 TT350 that I bought new. It has been ridden hard abused and handed down several times. It is still in the family and used as a buddy/beginners bike. The head has never been off of that bike! My 2k WR400 had a metal screen filter. I change oil almost after every ride. Only changed the filter when the rubber started looking bad. When I bought my KTM which uses two filters I decided to go with the Scott's stainless. I have well over a year on the bike which is ridden year round with zero problems. I know other KTM riders who have over two years on their bikes with them.

I use to clean mine in kerosene and then blow dry. Now, I just clean them with dish soap and water. I use an old hair dryer to dry them off. Takes only a couple of minutes. IMHO, I think they are a good investment. Especially, if you plan on keeping your bike for some time and change oil often. As far as advertised micron sizes take it with a grain of salt. The only thing that sort of substatiates it with the stainless filters is that we can know what type of metal cloth they use and its filtration and flow ratings/properties. I have found through my research that the advertised micron filtration size and flow characterics is consistant for the type of weave of cloth they use. By doing an internet search on "stainless steel cloth" you can find a ton of supporting data.

Good luck, Paul

Thanks for the info PMAUST!

I'm skeptical about this product. First, a 35 micron filter may be plugged up too quickly and cause oil starvation.

Second, Yamaha changed the filter for the 450's to paper due to the smaller oil capacity of the system and likely have an engineering reason that drove this change from the 400-426 models.

Third, and most important, NASCAR teams use both a screen type filter AND a paper filter. Considering that these folks have $ 50,000 plus engines, I'd think they have filtration of the oil well thought out.

If one looks closely at the stock 450 Yamaha system, the stainless filter is up in the frame, and the paper is on the engine. Does Yamaha know something the aftermarket folks don't?

The KTM guys did all kinds of talk on this subject. Try a search and be in awe at how much info is there. What I got out of it was they both(paper & SS) do a good job. The SS filter is more consistant at filtering and the paper filters had sections that filtered better and sections that filtered worse. Basically it just comes down to money and if you like to clean your filters or not.

I wouldn't put too much into manufacturers switching from metal to paper. There is a lot of money to be had by selling paper filters and it gets the customer back to the dealer on a regular basis to buy other things too.

Jim, I'd like to agree with you on this, but if indeed a mesh type filter was acceptable to Yamaha engineers considering they have two available that look very similar (PN: 1UY-13440 and 5HO-13440), and Yamaha went through all the trouble to design and specify a paper element; why did Yamaha change for the 450's?

APhantomduck, I have debated this subject at length. There have been good arguments on both sides. The bottom line is there has never been an independent study done on oil filters for bikes. I have seen very good studies and comparisons of automotive filters but, they never included stainless for comparison. So, the problem is it can be debated ad nauseam with no real conclusive results. What I can say with absolute certainty is that after more than a year my SS filters still flow much better than any paper filter I have ever seen. You just have to bench test one yourself to see that. I have yet to ever find anyone who has actually used the filters to say otherwise.

There are a lot of people using them in a variety of different bikes and there has never been a reported problem with their use or, as a result of their use. But, if there ever is, I'm sure we'll hear about it here! :)


You might be missing my point here. Up until this model year, Yamaha had used a brass screen filter on its YZ and WR models. These filters are washable and cleanable and last a long time. Why one would replace these with a $ 70.00 filter is beyond me, as they accomplish the same thing.

If Yamaha had determined that a 35-micron filter was good for the overall durability of the machine, likely they would have designed a filter to meet this requirement.

The new bikes filter was designed, according to my sources within Yamaha, to provide better filtering capability for these machines that now have less of an oil capacity. So, in a sense, Yamaha has engineered the best of both worlds for these machines; a stainless mesh in the frame to trap the big stuff and a paper filter for the final cleaning.

As for problems with aftermarket filters, I can tell you from experience as a dealer that we have seen some YZ/WR four stroke engines damaged from oil starvation; all of which had aftermarket filters of various makes. We have never seen engines damaged from oil starvation when the customer uses the OEM filter.

I spent considerable time talking with Ty Davis’s former mechanic about this subject. He is one sharp person, and has extensive experience with military aircraft. He shares my concerns. So much so, that in Ty’s bikes before the 450’s came out, Jim modified the OEM filter by adding a magnet close to the relief hole to attempt to pick up any ferrous metal not caught by the two filters on his bike.

I have good contacts within Yamaha in Japan. One of these contacts is the primary engine engineer at Yamaha for this bike. I’ll attempt to contact him via e-mail and get some answers.

and Yamaha went through all the trouble to design and specify a paper element; why did Yamaha change for the 450's?

Money. Both lower overall bike sales price and re-occurring filter sales.

Just my $0.02 worth.

APhantomduck, I am not missing your point I just didn't address it. Actually, the brass filters were nice because they were cleanable and reusable. But, they sure didn't look like they filtered very well. I mean you could see right through them! :) So, I agree with Ty's mechanic!

Are you saying that you saw bikes suffer oil starvation from the use of SS filters? As I am sure you know, oil starvation can occur for a variety of reasons. Cold starting, wrong weight oil in the wrong climate, dirty oil, et cetera. I have even heard of oil starvation occurring because of 10w50 oils not passing freely from the the oil pump spray nozzle.

I want you to know that I appreciate your input. Any information that you can get for us on this subject will be greatly appreciated. When you contact Yamaha, it would sure be nice if they could also provide a micron rating for their paper filters. Not just average but, the largest sizes passed. Also, flow rates would be nice. In addition, can you find out if the paper they use is resign impregnated or ??? and, how many pleates per inch are used?

Thanks for joining ThumperTalk! It is folks like you that make this site such a great resource.


The most recent info I've seen says Yams paper element doesn't filter down to 35 microns. (don't ask me where I seen it, I don't remember). as far as NASCAR is concerned, They rebuild their engines after every race,practice. I'd rather not do that with my WR. Higher restrictions on oil flow, mean more drag. I'm suprised race teams even bother to filter their oil at all! If you've ever seen the inside of a racing engine, you'd be amazed at how loose they are. If you change your oil regularly, and clean your filter often, I can't see any reason why a stainless oil filter is not a good investment. Unless, of course, you are a dealer trying to convince people to buy more filters at your dealership. By the way, I also have experience with military aircraft, and road racing engines, and I also run magnets (all drain plugs). :)

I have no problem with paper filters. I used them a lot on my XR 250 and XR 400. The only thing about Yamaha is that it seems like they are at least twice as expensive as Honda.

I manufacture filtration equipment for waste water and machine tools. It's one of the few subjects I post on that I actually know what I'm talking about. The Scott's SS filter is a good filter, the YZ426 brass filter is good and can be cleaned. The YZ450 filter is paper and it would be hard to clean without damaging it. I use the YZ426 filter because I can see any particulate on the filter and I can clean it.

Don't get hung up on all this micron rating BS, the range all these filters are in is fine. Just change your oil often.

I think its all relevent to how often you change your oil.

If you don't change it often , it might be a little more of an issue. Oil is cheap, filters are cheap. Do it. :)

Does the 426 filter work in the 450? Good thread. ---Mike

Actually its the same filter for, TT250R, WR250F, WR426F, YZ250F, YZ400F, YZ426F, and YMF 350/400 quads.


Precisely my point. NASCAR teams use both a mesh type filter AND a paper filter. They indeed do rebuild their engines after most every race. Most teams run anywhere from a 12 - 18 quart system. The WR 450 hold about 1 1/4 quart. The power generated per cubic inch by our YZ/WR 450's are likely close to that of a BGN or WC motor.

Consider the facts cited above and determine for yourself what protection you feel appropriate for your engine.

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