Engine Oil question


I''m about to do my first oil change on my yz426f -02. I have read the oil specs in the manual and I have an oil that would do, but! In the service manual it says that I sholdn't use an oil with additives or oils with a grade of CD or higher. On my oilcan it says API SL-EC/CF. What can happen? What is the CF?

I hope someone could help me, I need to change the oil now And would like to use this oil.

Sorry for my bad english!


Guztav from Sweden

just make sure on back of the oil bottle it doesnt say energy conserving, or it will cause the clutch to slip

API SL-EC/CF. What can happen? What is the CF?
CF is a commercial grade (for trucks and commercial vehicles), and CF is a fairly old, obsolete standard. The EC that I bolded in the quote is a concern, because it suggests that the oil is fortified with friction reducers that MIGHT cause clutch problems.

Based on the grading on the label, it doesn't look like that good an oil, frankly. Is it an automotive oil? I would rather see SG/SH, CI-4, and JASO MA. GL-1 would be nice, but I know of only one oil graded with that.

But the oil seems to be good enough if you read the manual. Or have I missunderstod something?

Thank you very much for answering btw! :)

do u guys get different oil over in sweden

Not that I know of...But in the manual it says API SH or higher. This oil is API SL.

I've changed the oil now and the clutch seams great. Comes up on the backwheel on fifth gear still so... I dont think it's any problem. But oh my god how much metal it was in the oilfilter. Is this normal? It were a paper filter and I installed a "metal" filter. What is best?

And guys, and possible girls, how often do you really honestly change the oil and filter?

Bad english again...

i change the oil every other ride

I use a Scotts stainless steel oil filter, and I clean it at every oil change. I change oil every third ride day. Until I had the oil you are using tested, I would change it every ride.

The issue is whether or not the oil can retain it's viscosity over time when used in a transmission. Find an oil testing lab like Blackstone and send them a sample of your used oil. Pay particular attention to the results for SUS and Cst viscosity at 100 C (212 F). It will show what your oil is and what it should be.

Most oils that are not correctly blended for transmission use will drop down in grade very quickly when used as a gear oil. Your 5W-40 may become a 5W-20 in a surprisingly short time.

Metal in the filter is a normal thing, especially because of the clutch and transmission. The longer you leave the filter alone, the more will be there when you take it out. The thing to do is to watch for a sudden change in the amount or kind of chips you see. This could mean trouble.


I'd be more prone to trust that one. SG means it will have a good compliment of anti-wear compounds in it, and JASO MA says it's good for your clutch.

But there is still the question of how well it will keep its viscosity in a transmission, so I would still send off a used oil sample after about 5 hours of use to see what condition it is in.

I just figured that API SG not suits for the recomendation of api SH. Hmm... I just want a good priceworthy oil, is that so hard to get?

SG and SH are very near the same. As with any product, everyone wants high quality at a low price, but that's always been hard to do.

Like the last one, the label info is OK, so you could use it, but I would not use it for longer than 2 rides until I had tested a used sample.

Yeah, it would be great to do that. But I don't think that theres any lab around where I live. But I might check into this. Thank you for your advice!

I ship mine to Blackstone Labs. That's still within the U.S., though. See if there's one in Europe somewhere that isn't going to cost too much for the shipping. Your main interest will be in the viscosity of the used sample at 100 degrees C.

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