Conventional "RACING" oil or not???

[chuck hahn]

I just wanted to be sure and not make a bad choice in oil..seeing that that was the issue with this engine from the get go. If you guys sayn that todays basic conventional oil will withstand the foaming then thats all I need to really know. Just wanting to understand and decipher all this " anti foaming" jargen before i blow this engine up. Thanks for the links and input guys.

[chuck hahn]

Thats JP was a typo Dale...I couldnt remember the name of the oil at the time...H4 was the stuff...HA HA.

[rustybronco]

If you guys sayn that todays basic conventional oil will withstand the foaming then thats all I need to really know.

I don't recall anyone suggesting you use a basic conventional oil... quite far from it as I recall.

[chuck hahn]

Well as I took things...todays conventional oils are capable of withstanding this "foaming" phenomenin...was i not interpreting the postings correctly? And just what is the author of the article referring to when he states "todays oil technology"???

[rustybronco]

There are conventional oils (dyno), synthetic blends (synthetic- conventional), hydrocracked synthetic oils (synthetic as a marketing term) and true synthetic oils, plus a whole gammit of additive packages for each and every type of oil available.

Just go with Rotella Synthetic 5W40 or Amsoil and be done with it.

[koolaid_kid]

Well as I took things...todays conventional oils are capable of withstanding this "foaming" phenomenon...was i not interpreting the postings correctly? And just what is the author of the article referring to when he states "todays oil technology"???

You are correct. A synthetic is good but not a requirement. I am an engineer and I am trained on how do do research. What you really should use, Chuck, is what everyone else uses: Rotella T 15W 40. I have asked my friends who also work in the diesel industry, and they concur.

[rustybronco]

I think you will find that Rotella 15w40 is not even close to being as shear stable as Amsoil 20w50. When I used Rotella in my '82, the shifts were starting to get 'clunky' at about 2.5K, when I used Amsoil it was still shifting nice at 5K miles.

Just one bike so take it for what it is.

[Nessism]

I think you will find that Rotella 15w40 is not even close to being as shear stable as Amsoil 20w50. When I used Rotella in my '82, the shifts were starting to get 'clunky' at about 2.5K, when I used Amsoil it was still shifting nice at 5K miles.

Just one bike so take it for what it is.

From what I've read over at the Bob is the Oil guy forum, you can run that Amsoil until all the acid buffers are used up without much concern about the viscosity shearing down. I'm not sure how many miles that would take, but suspect it would be well above 5000 miles. From that standpoint Amsoil helps offset it's high cost. Still though, that cost is a killer. And my inner mechanical sympathy makes it hard to run the same oil for 8000 miles in an air cooled motorcycle.

[rustybronco]

Ed, I'm glad someone confirms what experience I had with that oil, and yes, I would be willing to bet that oil would be shear stable long after 5,000 miles.

The worst oil I've ever used in my '82 was Advanced auto's 20w50. I drained that stuff after using it just 90 miles. Absolute garbage! Quaker State conventional 10w40 was good for 800~900 miles then the shift quality started to go south. I tried a few different oils just to see what they would do and that Amsoil was quite the standout in my opinion.

[koolaid_kid]

I agree on the mileage. 2-3k max, especially for a special engine like that Yamaha. Which leaves the door open for oils that won't go as far as the Amsoil.
Spend the money on the Amsoil, or change it more frequently for dino oil. Your choice.