I won't run without it.
Normally, when I have to redo a break in, I'll deglaze the cylinder, and run some Byron's 10% with 16% oil, and add 4 caps of straight castor to the gallon.. I wasn't looking when I picked up this last gallon, it already had 20% castor / synth blend. I added the customary 4 capfulls of castor anyways. It leaves a pretty smoke trail. I'll order another sleeve and ring from MECOA. If it still does it, I'll just go with it. Too bad I can't do it like a car - fill the crankcase with 90 weight and put it on the auction block. LOL