But, as hard as I ran my KX, I did notice when I started running 32:1-40:1. It surged worse. Running 50:1-80:1 I noticed it wasn't so bad.
Not implying that you didn't already know this, but just for riders who may not understand what's happening:
Running a rich oil/fuel ratio (premix)
LEANS out your jetting. That's correct...it's like using a smaller pilot/main jet. Without increasing the size of jets in your carburetor, transitioning to a 32:1 premix from a 50:1+ will cause surging typical of a lean running motor. It has in fact become a lean running motor when you've about halfed the amount of fuel the motor is getting by increasing the oil ratio. The opposite is true when you transition from 32:1 - 50:1+ the motor will run rich unless appropriate jetting changes are made.
I heard that even though Amsoil has a "full synthetic", it is not. I was told that it still has some form of bean oil in it. And that is the other thing...bean?
This is true, but it's not an issue to cause alarm. Synthetic oils today are a combination of ester packages and formulas to meet a desired criteria/goal. Amsoil has likely added some blend of esters formulated by Castor bean oil to augment their add package. Doesn't mean it's castor oil, and it curtainly doesn't mean it's not synthetic. Each of those claims would be totally false. It just means Amsoil is takeing advantage of a particluar function of castor oil by including a very specific "ingredient" that performs similar to the compound from which it was created.
And now to throw my flavors in,
I run Torco GP-7 @ 50:1. I'll likely switch to Amsoil Dominator after I finish off my Torco supply. Although Maxima Super M looks good too.