Well, Wendell, luck to you, but I follow a philosophy, more in line w/ "Follow Mfr recommendations", because I (had) a new $750 saw that ran 2-days before it locked a piston ring down tight, and they wanted $700 (OEM piston/ cylinder) to repair out of warranty, 3-yrs later. I (thought) it had run out of gas (was at end of cut anyway, by coincidence), then had back problems, so never tried to fire back up until 2+ yrs later outside warranty period. I had run 40:1 crapsman, (tho book said 50:1). I FIXED it w/ a $12 piston ring and ignored a very small scratch. There was a film of carbon so small/ light, you (would have) thought made by Magic Marker, but it had ring locked down solid. I have a good number of hours over past years and suspect compression has come up as ring has seated, but I NOW use ONLY (Synthetic) at 50:1. There was also the guy running the TCW oil, where your book says "Never use TCW in air-cooled..", so best of luck (again) on your "Marine Stabil"; NOT for me