Using "car" oil in a WR

My dealer tells me that using "car" oil prematurely wore out my clutch plates. He told me that he could tell that I used car oil as soon as he took the clutch cover off. The plates were glazed over. The guy has never lied or jerked me around in the past and I do normally trust his judgement/advice. Is there a difference with using motorcycle oil?

I have a good article that says yes. Motorcycle oil is not that much more expensive and worth it in my opinion.

A number of factors enter the picture:

1) The brand, type and viscosity of "car" oil you using. Not all oils are created equal. If you meet the Yamaha owners manual specs you should be OK.

2) Frequency of oil and filter change.

3) Use of your clutch. It is used just starting out under easy load or is it fanned like a 125 coming out of the turns. If you fan the clutch a lot under heavy load you can toast it quickly, regardless of the type of oil you are using.

4) Heat. Under extreme temps oil and clutches cook a lot faster than normal.

As you see, there may be more than just the "car" oil at issue.

For what its worth I only use "car" oil that meets Yamaha specs. Note that I do not abuse the clutch. I don't have to with the torque of a '99 YZ timed WR400.

Eric in WA

18 months on my bike (riding twice a week) with Mobil 1 and no problem with clutch...


MotoGreg - The voice of absurdity

'99 WR400 - 'Cause thumpers rule and two-strokes drool!

'92 GSXR 7/11 (But I wanna get a dope 916)

I might let you visit my photo album for $3 - ENTER AT YOUR OWN RISK - DANGER LURKS WITHIN

Some dealers have an interaesting way of looking at things.. I have a 99YZ bought new in DEC 98 and just replaced clutch not because it was slipping (I guess I just owed it that much) I run nothing but synthetic oils ie.. Amsoil,Redline. My riding style emulates that of a two stroke rider on a 125 thought for sure the clutch would have been toast but not so. Damn thing looked brand new? COULD IT HAVE BEEN THE OIL?? I guess the world may never know. :)

Yes you should really not use "car speific" motor oil in your bike.... mostly thanks to our US government.... 1st, the gov. emissions control standards want your car catalytic conv. to last 100,000 miles, and certain elements in oils like zinc and phosphorous (called extreme-pressure additives) that provide "last line of defense" protection under lubrication breakdown conditions, also slowly clog or reduce the life of cat. conv's..... so.... lets remove these protective additives!... says the car manufacturers.....2nd, the same emission rules mandated the oxygenated fuels your area of the country may now be forced to use.... but these cause a reduction in gas mileage which doesn't look good on the mileage sticker on the new car.... so lets add "friction modifiers" to the oil for less internal engine friction in your car engine .... which doesn't have a wet clutch like your bike, and COULD cause your wet clutch to slip.... The way you know an oil to be "car specific" is by the designation SJ on the oil bottle or case........ Now, does that all sound like an oil commercial?...if it does thats because I read it on an oil manufacturers website.... and had been using 20/50 in both my streetbike and dirtbike... with the dreaded SJ rating, and my streetbike has been occaisonally making a "GRAUNCH" noise under medium-hard launches... no noticeable slippage in either bike.... But I will now be switching to non SJ rated oils.... I have not looked over the oil shelves at the auto parts store yet to see how many if any of the oils they sell meet this standard.... apparently the days of quality 20/50 "racing" oil from the auto parts store for 99 cents a quart are over.

Just wondering what kind of oil were you using??


I guess you can believe anything anyone says about oil. My personal experience ,I have used Castrol 10-40 or Castrol 20-50 in both 2 and 4 stroke for the last 15 years and have never had a bottom or top end failure,senior A enduro rider. So at least in my case, I've had no need for $4 a quart oil.

Yeah Bliz.... basically I think like you... and I feel somewhat betrayed by the oil manuf.... You see..if you go look at the oil bottles you are using you will probably see an "API serv. rating SJ".... and if you find a 5 year old oil bottle it will say "API serv. rating SE" which is the correct stuff for our engines.... They removed the "extreme pressure additives" and added "friction modifiers"..... So despite the fact that it is the same brand and viscosity rating, it is NOT THE SAME as what you used to buy.... this is why I feel somewhat betrayed.... I have been using Valvoline 20/50 "racing" oil for many years and can usually buy a case of it on sale for a buck a quart.....But now it has the "SJ" rating and I have to decide whether to believe the 'tech jargon' and its importance.....I do know for a fact that my clutch on my 1100 street bike now occaisonally makes that strange noise , but I don't know why (but I would say it doesn't slip, but I don't hammer on it much either).... If I can find a "racing" 20/50 with the "old" SE rating that is probably what I will buy.....or I might continue to run the "SJ" stuff till it proves to me that it ruins clutch plates (the clutch plates on the streetbike are 20 years old anyway).... I'm figuring a racing 20/50 is still going to protect well despite the removal of the "extreme pressure additives".

Thu Aug 31 10:40:53 2000

There is a difference between automobile engines and motorcycle engine requirements. Motorcycles, particularly Japanese designed models, use their engine oils in the transmissions and clutch systems. These applications place unique stress on motorcycle lubricants. The maximum engine output per liter for motorcycles is 1.5 to 1.8 times that of automobile engines. Similarly, the revolutions at maximum output are 1.3 to 2 times that of automobiles. Further, motorcycle engines are small and light weight. This results in a small thermal capacity in motorcycle engines which causes engine oils to reach temperatures as high as 320° F. The above differences logically lead to the point that a motorcycle-specific engine lubricant can be formulated to address the unique requirements of the motorcycle engine. The major modifications would be in using a more shear stable viscosity index improver (VI) which provides viscosity retention when run through the motorcycle transmission gears. Automobile oils using less shear stable VI components which will fall out of grade or suffer viscosity loss rapidly in motorcycle applications.

Further, due to the high heat and the RPMs motorcycles encounter, ZDDP and phosphorous are needed to prevent cam wear and oil oxidation. Lastly, care must be taken in the choice of friction modifiers in motorcycle oils to prevent clutch slippage. Current auto oils of API SJ quality contain a large amount of friction modifiers for increased fuel economy as well as limits on zinc and phosphorous content thus limiting their use as motorcycle lubricants. They are fine for auto engine use but inappropriate for use in motorcycle engines.

The Japanese manufacturers address these topics in SAE paper number 961217 entitled, "Study on 4-Stroke Engine Oils For Motorcycles: Engine Characteristics and New Specification Oils" dated May, 1996; available from the SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0007. Telephone: (412) 776-4841; Fax: (412) 776-5760.

My personal choice is to change the oil at the very least after every other ride, this depending on the type of riding. Always use Yamalube as the manual calls for. I'm hesitant to use synthetic oil. (Have used it in the past on a KTM, but when changing oil frequently, I'm only padding the wallets of the oil company). The cost of changing it at these intervals makes no economic sense to me. And I firmly believe that changing oil often has long term benefits to the WR.

However, someone at Yamaha will probably be able to retire early based on the number of oil filters I have purchased. :)

Why don't you clean the filters and recycle them? You can clean a bunch at once, and change them with each oil change. Or, buy the K&P stainless steel filter.

Scott F

I've noticed this topic has changed to talk on oil filters. To set the record straight the WR400 does not have a paper filter. The stock filter consists of a very fine pleated metalic screen that is potted in two metal end caps with silicone rubber seals. :)

The stock filter can be cleaned and reused, just hose it off with some contact cleaner to remove the grime, let it dry and reinstall it. Be sure to inspect the fine wire mush screen, as it tears easily. It is a good idea to keep an extra filter on hand just incase the filter is damaged during removal. :D

I don't think it would be a good idea to buy a sintered metal oil filter from Scotts Performance because this type of filter has a much greater pressure drop than the stock filter. :D

Besides for $70 you can buy 7 stock filters and that should be enough to last 7 years. I'm still using the filter that came with the bike and I can see it lasting atleast another eight months. Of course I have another filter on hand just incase I tear the screen. :D


FLIB in SoCal

'00 Canadian WR400 with Thumper Bar Risers, Renthal "Button" Bars, Clarke Tank, Guts Tall Seat Foam, WB "Hawkins" Pipe, Race Tech 5.4kg/mm Shock Spring, WB Skid Plate.

A Yamaha mechanic told me that the Scotts filter is too restrictive they had problems with people who run them not getting enough oil to the head to lube the cams.


MotoGreg - The voice of absurdity

'99 WR400 - 'Cause thumpers rule and two-strokes drool!

'92 GSXR 7/11 (But I wanna get a dope 916)

I might let you visit my photo album for $3 - ENTER AT YOUR OWN RISK - DANGER LURKS WITHIN

I don't know what sintered metal filter you are referring to. The K&P filter that Scott

's and others sell is made from a superfine stainless steel screen. I have spoken at great length with the designer of this filter, and he assures me that it flows more than a stock filter. If you have any questions, call Kip at 303 697 5821.

Scott F

Originally posted by FLIB in SoCal:

I don't think it would be a good idea to buy a sintered metal oil filter from Scotts Performance because this type of filter has a much greater pressure drop than the stock filter. :)

Scott F,

The stainless steel filters seem like a viable option (Scott's has them for about $70.00). Some of us old timers remember when cars had reusable oil filters. As far as cleaning the OEM filters, I'd rather spend the $10.00 and eliminate any chance of paper pieces finding there way into places they shouldn't be. How many times do you reuse one of them before you dispose of same?

I do the same thing as FLIB. I've been using the stock filter since December of last year. I see no need to use anything else.

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