how much is too much metal in the oil filter?

I've had my 01 WR250F for almost 2 years now. I ride pretty much at least one to two days every weekend, on average about 40 miles each time. I change my oil every 3-4 rides with Yamalube 4R. I've never had a major mechanical issue with the bike until now.

I just changed the oil and man was there a lot more metal debris in the oil filter than ever before. It was definately excessive, because it took quite a few wipes with a shop towel to clean out the oil filter cavity. The first couple of wipes were enough to cover the surface area of my index finger.

I consulted a friend who's first thought was check the clutch for signs of wear on the plates and inner/outer basket. I haven't opened it up yet, but I did check the metal shavings with a magnet and they are definately not aluminum.

I took some photos and put them up on my website. Here is the link.

photos of the shop towels

What do you guys think? Are these signs of potential engine failure? Crank? Any ideas?

I'm trying to be proactive and avoid a major failure, so I'll probably have the motor checked out just to be safe.


Ideally there would be no metal at all. It does not look bad to me. You should have seen my wifes 2000 4x4 Yamaha Wolverine quad. It has a metal screen oil filter. the first oil change was scary with way too much metal, the second much less. The quad still runs just fine. Yours looks like a trace amount that I would not be concerned about. That is what the filter is for.

Unfortunately, the photos don't really do justice to how much metal there is. It really does look excessive in person, especially for a 2 year old bike.

My friend had the same, sudden increase in the amount of metal shaving just before her crank broke.


I went through the same thing on my 01 WR 426. Based on most of you photos it looks normal, although that one pic shows a lot more that I have ever seen. I posted the same question here and asked dealers, and even had REV mag respond. Basically I feel comfortable that it is normal and I don't much worry about it anymore. Almost all of my flacks are non-metallic, so I am still not sure where they are coming from. Try and find my old post, one had a ton of miles and said it had always happened and no ill effect. Hope it helps

The rule for metal in the engine is "scream it until something comes apart and then you will know what was wrong".

That is all good, but you have to remember. I know what amount of shavings there are normally. This isn't normal.

I could scream it until it breaks, but what will that get me?

It costs a lot less to replace worn parts than it does to replace all the parts that get damaged during engine failure.

I've decided I'm not going to take any chances. I'm going to have the motor disassembled and inspected as soon as possible. I'm not riding it again until I can be certain there isn't an underlying issue.

I'll do my best to take more pics and report back on what we discover.


If you get more un-normal quantities on your next oil change better split the cases...

BTW you can open the filter only without changing the oil and expect after every ride. I guess it is from the trany if you do not hear some strange sounds from the engine.

I agree with Sabin, it is most likey coming from clutch or transmission. You should split the cases immediately before more damage occurs. Hopefully it is just coming from your clutch basket(aluminum). Do you know if they are steel or aluminum particles? You could do major damage if you continue to ride it and something blows up. :)

The amount of shavings that you describe and represent are relatively similar to what I have had since new on a 2001 WR426 (The bike now has 9000km, with no mech problems).

So if it were my bike it would seem normal to me.

The only issue of concern is the relative increase in trapped material in the filter. Use a magnet to determine if they are flakes of Al or steel. The material trapped in my filter is Al, presumably from the clutch. Monitor closely any changes in trapped material over time.


Ben, My personal opinion is that it's not a big deal.

Well, I removed the motor and started to disassemble it today. I got it stripped down, but haven't split the cases yet.

So far, it looks like I wasn't wrong. There is about 0.5 mm of vertical free play in the con rod around the crank -- not good. There is also a nick in the cylinder wall about 1 mm wide and 6-7 mm long that pentrates the cylinder lining completely -- aparently some of the shavings got between the piston and the cylinder wall.

The top end looked good with no obvious signs of abnormal wear on the cams or shim buckets. There is actually minimal carbon build up on the vavle seats as well.

My buddy is going to split the cases and inspect for further damage, but doesn't expect to find anything significant.

I'm going to take advantage of the opportunity and go with a 262cc overbore (I think it is 80 mm bigger than stock), and hopefully an aftermarket con rod, and crank replacement.

I'm going to do my best to get photos of the damaged parts, but I don't have a digital camera at my disposal.

I'll update this post with more info when it becomes available.

It didn't really take much to tear the motor down enough to check the cylinder, piston, valves and free play in the con rod. I'd recommend it if you think you might have an issue.

I'm pretty sure that if I had just kept running the bike I'd be looking at a complete engine failure some time in the near future -- which is very costly as we all know.


What ever happened to your flakes? Did you get rid of them? If so, how? It seems to becoming a bigger issue on my bike. Thanks for the update.

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