Dirty Oil

[FastRC45]

Posted a few times now re: a new to me 07 450f. When I got it the oil level was low and it was thick/jet black. Changed oil/filter, rode for an hour before the timing jumped. When replacing the cam chain, the 1hr oil was almost as black as original, so I bought 3 Qts of cheap 10-30 and ran each for 10 mins or so before changing. Still dirty so 3 more changes (including 2 Qts of diesel spec oil) and it's not black, but a really dirty gray. Went to the desert this weekend on good oil/new filter and did 20ish miles, changed it, did 20ish more, changed again. The last oil change looks as dirty/gray as the 3rd 10 minute change. Did over 100 mi yesterday but haven't dumped that oil yet.

Bike doesn't smoke. Coolant is fine. Clutch has good feel/operates fine. I'm stumped unless there is a plug of gunk hidden away somewhere. I've had the left case cover off and it was clean, but I haven't pulled the clutch cover or right case cover yet. Any ideas???

[Goforaride]

I used to have a crf250. They have seperate clutch/engine oil. Whenever i would change the clutch side, the oil was a milky grey color. It was just from clutch wear. It did take 4-6 hours for it to turn tho.

[Goforaride]

Check this out. https://www.thumpertalk.com/topic/860136-2010-model-tranny-oil-color/?hl=%2Bgrey+%2Bclutch+%2Bside+%2Boil

[FastRC45]

Guess I'll be pulling the clutch cover when I change the oil. It has a GYTR cover, but no idea what's inside. PO wasn't afraid to throw some money at it (nice bars, FMF pipe, fastway pegs, Enzo suspension, etc) so I wouldn't be surprised if it's got something other than stock. But I'll check the aftermarket and see if anyone is selling aluminum plates for the YZ...

[Goforaride]

Guess I'll be pulling the clutch cover when I change the oil. It has a GYTR cover, but no idea what's inside. PO wasn't afraid to throw some money at it (nice bars, FMF pipe, fastway pegs, Enzo suspension, etc) so I wouldn't be surprised if it's got something other than stock. But I'll check the aftermarket and see if anyone is selling aluminum plates for the YZ...

Just go oem

[FastRC45]

I'm plenty happy with oem, was just asking if there are alum plates on the aftermarket to explain the gray oil per your experience with the honda... Otherwise I'm back to the drawing board on looking for a source of contamination... I only ride desert and am pretty gentle on clutches, so...

[Goforaride]

The only potential cause in my crf was a Hinson basket. I didn't have alum plates. Never even heard of alum plates. Whatever the cause, I am confident that it is your clutch.

[xy500]

My 06 yz450f has aluminium clutch plates as standard

[Goforaride]

My 06 yz450f has aluminium clutch plates as standard

I guess I just never really thought about it.

[grayracer513]

There are a couple of things at work here.  First, it's possible that the engine was so poorly maintained that it's taken that long for all the sediment to be removed.  Mostly with Diesels, but I've been accused by customers of having not changed the oil when it was charged for, based on its appearance.  More than once, I've offered the customer to watch me change it again, and then if it was not black again by the time I got his truck back to the service drive, he could have both oil changes free.  If it was, he would pay for both.  Never lost on that one.

 

The other thing is that the fact that the oil turns color is not in and of itself any indication that it's dirty.  Some oils will turn black on exposure to reasonably normal (at least in a dirt bike) tempertures, and some will turn black on exposure to fuel contamination, which occurs on cold starts, when you drop the bike, etc.  The better synthetics usually won't, but a lot of other popular oils will.

 

The YZF plain plates are steel, but the friction plates are aluminum.

[FastRC45]

Thanks Grayracer, was hoping you'd chime in. I'm running Maxima now, but the quick succession of changes I did to try and flush it were 4x with Valvoline ATV 10-30 and 2x with Ford motor craft diesel 10-30. I'll inspect the clutch pack when I dump the current oil, but like I said, it feels fine, operates fine, and I've never smelled a cooked disc...

[Mtrain730]

I bought my bike new and the oil turns dark fairly quickly just some thing to keep in mind. I wouldn't use that as a indicator or at least the only indicator of when to change it aside from any issue you might have going on. I run good oil and change it at about 5 or 6 hrs give or take depending on if I'm racing or trail riding. It gets darker long before that. I Think if you try to keep your oil coming out of your bike looking the same as when it went in your going to spend all your time changing oil instead it riding.

[grayracer513]

I change oil each third ride day (two if one was a race day), which could be anywhere from as low as 3 hours to as much as 8 or 10.  I use a top tier, motorcycle specific synthetic, and what I end up with is an engine that looks like this after 300+ hours.

 

Note how dirty the oil looks....

 

 

[FastRC45]

Mtrain, I can understand oil getting dirty after riding for a while, but the point of this exercise is to flush out the bike due to the horrendous oil that was in it when I bought it. Now that I've flushed it more than what I would consider a reasonable number of times to eliminate leftover gunk from the PO's oil, and it gets dirty/turns gray after 10 minutes, I think there's something else at play here which is what I'm asking for help to identify...

Grayracer, I haven't been lurking here long enough to accurately gauge your level of sarcasm, but the little golden puddle next to the crank bearing looks fresh out of the bottle compared to what I'm draining from my engine after 10 minutes.

The cheap oil was to flush only. When I ride it, I run maxima synthetic.

[FastRC45]

Not the best perspective, but this is what came out when I bought it

[grayracer513]

That golden puddle was the used oil that was in the engine when I tore it down, no clean up, and the remark was directed toward the comment regarding spending too much time to keep it that way. 

 

If your oil is turning gray, you might possibly have coolant intruding into the system someplace.  Head gasket, most likely, if at all.  Or, it might be that much sediment.  If you remove the left crankcase cover, and look in behind the flywheel, there's a good sized drain back port that leads right to the sump screen.  You might want to see what sort of thing you can scrape off the bottom of the case near the screen.  Could help you figure out where you're at.