I used Seafoam several years ago to help all my 2 stroke engine to fire up without pulling the starter rope to death. Seafoam did the trick. Now that ethanol-free gasoline is available near me, I stick with it and also follow Stihl's recommendation of the oil to the gas mix and use Stihl branded oil. After about 6 years of doing it this way, I'm drama free, the chainsaws start every time regardless if it is 10 degrees or 80 degrees out.
I run ethanol-free gas in all my small engines, 2 and 4-stroke including in my fishing boat (150 and 15 HP four strokers). I would likely run ethanol free in my trucks if they weren't both diesels.