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Discussion Starter #1
Aaron--what does your oil look like in your 175 after running a race or two? Mine seem to be awfully dark and icky. What about you, Johnny?

evilsky
 

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Hey Scott,
It's funny you say that. The first couple times I ran it even after cleaning everything mine was also pretty dark after only a few runs. I kept cleaning it and switched to Mobil 1 and it seems to look a lot better, but yes for a while it seemed as though I got the same results as you.

Aaron
 

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yeah me too. seriously, after the first race the oil looked as dark as the old oil I first drained out of it. but I never took the bottom end apart so there was probably plenty of crud in there.
 

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Discussion Starter #4
The first time I saw how bad it was, i tore the engine apart to find out what was causing it. Couldn't find anything. So I cleaned it all up and put it back together. then I changed the cam and put it back and ran the last two practices and races. Since it only uses 1.5 quarts oil I change it frequently, but it seems to be really icky. So I tore it apart again last night (both side covers off, clutch, head cover, etc) and opened up the oil slinger. Well, I was surprised again at how much stuff was inside. I'd estimate it at about a good tablespoon or so of sludge, pretty heavy silty stuff.

And worse, something I have only mentioned to JB, was that there seems to always be a silvery sheen to the oil—not really a sheen, but a silvery fine grain material suspended in the oil after running that I ahve drained after a short run. So I let the oil sit in a container for a few hours, and there is a little of this silvery stuff in the bottom of the pan. But I can't really find anything wearing away. I am thinking that it is from the skirts of the pistons wearing away.

But I think it's time to switch. Mobil 1 is synthetic, isn't it?

scott stumped. More thoughts?? Comments??

PS. JBranson also said he had stuff in his oil too. But when I change oil in my other bikes, it comes out clean. (generally, the way you would expect it to look)
 

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Drag a magnet through the oil. Does it come out with shite stuck to it? If so, you've got issues. Stop the clutchless shifts....

Otherwise, its clutch fibers and ring blow-by that's making the oil dark.
 

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Discussion Starter #6
just drug a magnet through the oil (yeah, i still have it) and I would say that basically nothing of any import came out attached to it . . . .

Good news, I guess.

s
 

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quote:
just drug a magnet through the oil (yeah, i still have it) and I would say that basically nothing of any import came out attached to it . . . .

Good news, I guess.
Always good to hear. When I rebuilt my CB450 two years ago, I was amazed by the amount of sludge/crap in the bottom of the cases. Took me a while to get it all out. 30 year old engines, ya know...
 

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I agree with Rob. Mostly clutch dust and very fine aluminum.

I use either Mobile 1 20-50w or Royal Purple Racing 41.

The Mobile 1 is pretty dark to start with in the thicker grades. The Royal Purple is of course Purple so you can't tell much there. When I drain the oil I get what look like swirls of silvery stuff in the oil, extremely fine, looks almost like an oil slick on top of the oil. I see very little if any solid matter in the oil after I strain it. I strain every oil change through a fine filter to look for debri.

Using dyno oil you WILL burn it somewhat in these engine during a race. Running these things for ten laps at 12k rpm gets them very warm, it will "roast" dyno oil somewhat. Mine comes back to the pits with the entire head spit spizzling hot..literally. I would say that synthetic is a must on these engines if you expect to keep the valve train alive. The crank and tranny are probably not an issue. Running Royal Purple I've noticed the oil supply side of the head is noticably cooler than the down stream end of the head.

The only thing I really look for is flakes of chrome (rocker pads) or pieces of rubber (cam chain tensioner). Mary's mostly stock engine came back from it's first race with not the smallest bit of garbage in the oil. I very, very thoroughly clean and engine when I put it together so I know that anything in there came after, not before. You will notice after some time on the track a fine black silt that gathers in areas of crankcase, that's probably the clutch material. I've never seen a honda engine that doesn't produce this stuff.
JohnnyB
 

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aaron, are purple and brown still your favorite colors? they don't really do it for me but whatever chafes your dong...
 
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