YZ426 Debris in filter

I picked up a 00' 426 recently for a good price, starts 1st kick and rips like it should.


However changing the oil filter revealed a bunch of debris, imgur album below.



It seems to be a mix of steel and aluminum, but the black gunk and flakes escape me.  :(



Since its still kicking hard, I was planning on running it another 2 hours and seeing if there is a comparable amount of crap in the filter. But is that a sensible thing to do?


Any advice appreciated, since im new to this kind of thing.

Black junk is probably clutch friction plates. Wipe it out and follow your plan to recheck in two hours.

Might not be a bad idea to take the clutch out and measure the parts. Some guys ride the clutch constantly and abuse them.

By the look of things, that oil filter has about 5 minutes of run time on it.  That amount of debris is far below what would normally be present after a normal oil change interval of say, 4-6 hours.


The black could be a number of things, but it's more likely than not the clutch debris Wm1 mentioned.  In addition to that, you'll find aluminum, usually from the clutch again, and fine steel from the collection of gears involved.  The engine shares its oil with the trans and clutch, and transmissions always shed metal into the oil. 


Cause for alarm is a sudden increase in the amount of any sort of junk you find, or the appearance of steel flakes, squarish in shape, and 1-2mm in size.  The flakes would mean a bearing race spalling off.

I'll put another 2 hours like I planned on it then, and inspect the clutch as well as seeing if its the same story with the filter.


Thanks for the help, i'll get back and post the results soon as i'm done, but i'm waiting on parts so it could be a few days.

On my crf the crankseal went sideways causing metal shavings


That's one of the reasons that a YZF doesn't have a crank seal.  "Parts that are left out of a design cost nothing and cause no service problems." 


~Zora Arkus Duntov

That's one of the reasons that a YZF doesn't have a crank seal. "Parts that are left out of a design cost nothing and cause no service problems."

~Zora Arkus Duntov

I did not know that about a yzf thanks

I'm a honda rider

I had a slow accumulation on metal,, after a season it got loud clunk on decell. Crank main bearing ball delaminating, and inner raceway of that bearing began to pit from that ball.

Sorry, going to be a few weeks before I can ask for an opinion on second filter inspection...




I done &%$#@!ed my thumb and knee up.  :banghead:  :foul:


Ill post 2nd inspection here asap.

Watch this space!

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