Confirm my gray transmission oil suspicion

[cr250john]

I have been maintaining my CR250 & my two sons CR80's for a number of years. I change the transmission oil at least every two rides and most times the oil comes out only slightly darker than it went in which shows normal clutch wear.

Recently my 15 year old has become quite an aggressive rider on his '01 CR80 and the oil has become VERY dark gray after only one afternoon of riding on an intermediate mx track. He has learned that feathering the clutch and keeping the rpm's up coming out of turns has helped his riding greatly. Every week now I also have to adjust the clutch cable at the engine side as there isn't enough adjustment at the clutch lever end and I'm almost out of adjustment on the engine side.

So my suspicion is that the dark gray oil is from the stock aluminum clutch plates wearing away. I say that because of the constant adjustment I have to do to keep proper clearance at the clutch lever side. Have you seen this before?
I'm using Mobil-1 15w-50 synthetic oil in the transmission.

Would steel clutch plates work better as a replacement for the OEM aluminum plates such as EBC sells as a clutch replacement kit?

Your thoughts?

 

[MikeT]

My '96 YZ125 has steel plates in it from the factory. The bike still has the stock clutch in it after all these years. The steel plates for the most part keep the oil relatively clean. I think they are a good idea to keep the clutch lasting longer. BTW, the friction plates will still wear, its just that their wear wont be combined with aluminum plates that wear quickly.

MikeT

 

[Durt Cycler]

John, I would switch to steel clutch plates since aluminum plates create alot of debris ( grey oil). I have steel plates in my CR and I get no debris in my oil when it comes time to change it. EBC, Barnett, Hinson, Versah, KG are all good OEM replacements. BTW if you are having problems with clutch adjusting maybe you should try to run a wet clutch gear oil in the bike and see if it helps.

 

[cr250john]

Thanks for your opinions!

I have an EBC clutch replacement on order. My son will be riding a Hare Scramble in a couple of weeks and I don't want to be caught short before a race.

The kid is just WAY faster than me these days. Maybe because he's 35 years younger than me... :D

Thanks again!

 

[KawieKX125]

I am not sure if you really want to use the aftermarket clutch. I have never had good luck with them, and I think the little CR's have bad clutches to start with, so I would be suspicious. At least dont use the heavy springs. The grey oil is not to worry. Just change it often and you will be set. If you use ATF, there will be little to no debris in the oil. At least that is from my experience.

 

[skhasky]

I agree. Stick with the factory clutch. If you want steel plates (not a bad a idea) find a similar model tha uses the same size plates, but made out of steel and install them.

 

[thomas123]

i'm no expert, but I hear that synthetic oil can make a clutch slip more than it should, try using non-synthetic and see if that helps...

 

[cr250john]

thomas123

The Mobil-1 15W-50 synthetic oil is a Non Energy Conserving (Non-EC) oil that does not contain the friction modifiers that "EC" oils do.

You can tell an "EC" oil from a "Non-EC" oil by looking at the back of the oil bottle. In the lower portion of the API circle it will state "Energy Conserving" or be blank. Non-EC oils will be blank.

btw - I have used Type-F ATF in the past also with good results.

 

[NO HAND]

Originally posted by cr250john
...I also have to adjust the clutch cable at the engine side as there isn't enough adjustment at the clutch lever end and I'm almost out of adjustment on the engine side...

Don't forget to leave some freeplay in the clutch lever. Even the manual tells you to have at least a few mm of freeplay. The reason is that once the clutch is hot, it swells and uses some slack from the cable. If your cable was tight already, the clutch then starts to slip without touching the lever. This will cause the clutch to wear out faster and will show in the transmission oil.

 

[cr250john]

No Hand

I believe that may be what started the problem. My son didn't realize the clutch was slipping because of a tight cable (lack of free play) since he was having such a good time. There is sufficient free play remaining and I have it adjusted properly now but I can tell the disks are getting thin.

Good catch!