As far as fuel troubles go, ever since I started using the premix 50:1 stuff that they sell at Home Depot, I’ve had zero problems. It contains zero ethanol and burns real clean. I even have a Stihl leaf blower that was hard to start, but once I started using that fuel, it starts by the second pull.
My new saw seems to be pretty picky with fuel. I bought the premixed fuel for the first time ever and it ran like a top. It'll be all I run in that saw now.