Hi. Hope I'm in the right spot. Lifelong mechanic/car/motorcycle guy. Never met landscaping I couldn't do. Not afraid to do house stuff, but not my bread and butter. All metalworking. No woodwork except for the basics.
For years, I have had a line on Milwaukee stuff at a hefty discount off...
Lot of good advice here. I run a lot of Echo saws. They respond well to tuning. That said, you might be asking a lot from that saw. One of my smaller saws is a 16" bar on a well-tuned 50cc engine and it does fine with a 10" tree. I can't imagine a 20" on a 40cc; that seems like you're not...