I have been adding Honda HP2 oil to Stihl MotoMix and converting it to 32:1 since my saw was brand new. It’s an amazing oil! Odorless when running because of the fuel type. My saw is a manual carb Stihl 261 I bought new last year, I pulled the muffler off yesterday and the piston and cylinder don’t have a single mark on them. Hour meter shows 6 hours run time now. Exhaust port was very clean!
My high speed adjustment on the carb is all the way open as rich as it can go, saw still revvs to 14,600 while pulling the 20” bar/chain on it. It is a BEAST of a saw. I’d have to remove the limiters on the carb to richer it up enough to drop the RPM’s or get it to 4 stroke.
I just keep the air filter and saw crazy crazy clean, and I think it’s probably gonna last forever. Been over a year since I got it, and I’m super happy with it. It just starts/idles/runs so well.