15 replies to this topic
  • etuke

Posted August 07, 2012 - 05:00 PM


just bought this yz426 and its my first 4 stroke,the guy who owned it said he used the universal 20w50 from yamalube.I went to yamaha here and asked for the oil to change it and thats what he said to use to.Is this oil ok for this bike or should I buy something else.Not alot of options here for the weight oils.I can get castrol motorcycle oil 20w50,mobile1 synthetic 20w50(expensive) and a motomaster(canadiantire brand)motorcycle 20w50.I have always used castrol in my cars and found it good but I think the castrol isn't synthetic.Guy at yamaha told me the universal stuff was semi synthetic.The mobile1 and motormaster oils are like $20 a quart here,the yamalube was $9 and the castrol is $6.

  • DC_Excitement

Posted August 07, 2012 - 05:57 PM


amsoil 10w40

  • frankie_b_jr

Posted August 07, 2012 - 08:56 PM


Glad to know i'm not the only one. Castrol 10w 40. I should switch to 20w 50 because of high ambient temps here (lows around 80, highs pushing 110).

  • etuke

Posted August 08, 2012 - 02:53 AM


so 10w40 would be fine to run in these bikes?I notice my clutch dosen't release well from cold and was thinking it was due to thicker oil,if i put it in gear and try to push it cold with clutch in it will lock the back wheel.I ran atf in my 2 stroke and the clutch always worked good.

Edited by etuke, August 08, 2012 - 02:55 AM.

  • DC_Excitement

Posted August 08, 2012 - 03:28 PM


10w40 is the recommended oil, i believe its in the service manual. yea the ambient temperature does factor in, but overall most people run 10w40

  • grayracer513

Posted August 08, 2012 - 04:08 PM


I don't know if most people actually run 10w-40, but most should, except for during the very hottest parts of the summer (ambient temps always above 95 or ever higher than 110℉).

The single biggest concern with an oil to be used in a YZF is whether it will hold up under the stresses of being used to lube the transmission. Almost no automobile oil will do that, most truck oils won't either, and up until recently (5 years?), the majority of motorcycle specific oils wouldn't either. The trans beats up the additives that allow a 10w base stock to behave like a 40wt at operating temperatures (160℉ and up) at such a fast rate that in two hours of use, a lot of 10w-40's will have turned to something more like 10w-25. If you use cheap oil, change it every ride.

JASO MA/MA2 was supposed to have addressed this issue as well as the question of wet clutch compatibility, but unless the oil carries the MA/MA2 seal on the label, it may only comply with the clutch friction part of the standard. Full synthetics such as Amsoil MCF, Mobil1 Racing 4T, etc. are the safest bet.

If in doubt, $25 will get you an analysis of your used oil from Blackstone labs.

  • ss55539

Posted August 10, 2012 - 10:55 AM


i run T6, synthetic and its not too costly so i dont feel bad about changing it often

  • etuke

Posted August 11, 2012 - 12:27 PM


So if I find a oil with the JASO/MA rating then it should be fine?Or does it need the MA2 rating also.I saw some shell rotella atv oil thats wet clutch and has the jaso/ma rating for $6 a ltr today.

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  • buick_gn

Posted August 11, 2012 - 12:30 PM


just use shell rotella t 15w-40

  • grayracer513

Posted August 11, 2012 - 04:04 PM


MA is fine, but you need to be aware of the difference between the statement that the oil meets or exceeds MA and the actual carrying of the JASO seal. Absent either of those, your only assurance is lab test data or a sample of your own oil.

just use shell rotella t 15w-40

Send in a sample of your Rotella after 2 hours use. Look at the measured viscosity at 100 ℃ and compare it to what it should be. It's an eye opener.

Rotella is a very good, high quality ENGINE oil. It's completely incapable as a transmission lube, however, and does not stay in grade under that kind of load.

  • antfizzle

Posted August 14, 2012 - 06:25 AM


I've used rotella 15w40 in my 2 stroke, and was using it in my 450 now also, are you saying the rotella is not a good choice for the 4 stroke???? Thanks

  • grayracer513

Posted August 14, 2012 - 06:57 AM


Rotella isn't a good choice to use in any transmission, 4T or 2T. Just doesn't hold up. As I said, it's a very good engine oil, especially for the price you can often but it for, but not for motorcycles sharing oil with the transmission.

  • antfizzle

Posted August 14, 2012 - 09:28 AM


Oh okay, I got it now, thanks alot

  • luckyguy19

Posted August 14, 2012 - 12:37 PM


I'm a big supporter of Rotella. I use 5w40 in my YZ450F in the winter, and 15w40 in my R1200GS. I would like to know where you saw the info on the Rotella not testing well after a couple of hours of use? Also, was that Rotella the T 15w40 or the T6 5w40 synthetic? It won't matter for my BMW because
the engine and trans are not shared, but it will mater for use in the YZ450F.

  • cereal killer

Posted August 14, 2012 - 01:24 PM


I'm a big supporter of Rotella. I use 5w40 in my YZ450F in the winter, and 15w40 in my R1200GS. I would like to know where you saw the info on the Rotella not testing well after a couple of hours of use? Also, was that Rotella the T 15w40 or the T6 5w40 synthetic? It won't matter for my BMW because
the engine and trans are not shared, but it will mater for use in the YZ450F.

You doubt the mighty Grayracer? He can probably tell by smell.

Edited by cereal killer, August 14, 2012 - 01:27 PM.

  • grayracer513

Posted August 14, 2012 - 02:49 PM



Anyway, to answer the question, I have not ever seen a used oil analysis of either flavor of Rotella taken from any shared engine/trans setup in which it stayed in grade. Viscosity loss was usually the only fault found, but often very serious. However, you may want to try your own. I've heard a rumor that Shell has addressed this issue to at least some degree, and that Rotella is now "better", whatever that means. Blackstone Labs will send you a kit for free.

This kind of thing happens with automotive oils because the tougher viscosity improvers are more expensive, and serve no purpose for 98% or more of the target market, so there's no point in adding them to the cost of the product insofar as the oil blender is concerned.

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