You guys are really talking me into liking this saw. I am a fan favorite of echo stuff but never gave them any thought for saws. I always heard stihl or husky and thats all I ever here about.
Why did the piston stick? Well I can only give an educated guess. I got it used in summer of 2020, and it pulled over strong, but would absolutely not fire at all. Upon rebuild / re-assembly it ran really lean and crappy. But I never cut with it so it never got damaged. Every time you touched a screwdriver on the L / H needles without even making the adjustment yet, it would lean out and stall, like as if just touching the carb caused an air leak. It sat since fall of 2020, and someone local suggested that I replace the intake bellows. I just did that and discovered the old one was not bad. So what I think happend is two things and maybe both of these things.
1.) I think I could have pinched the crankcase to carb pulse line when I re-assembled the first time. I paid extra attention to it this time and got it perfect.
2.) I took the diaphram side of the carb apart and found the air side of the metering diaphram under the metal cover was packed solid with wood finings, and it must have blocked the diaphram from moving and metering. Inside the carb was mint however but I still did a complete cleaning on every single hole.
It was not run low on mix oil as the rest of the piston was good, just one hot spot when it got lean. I will run this one at 40:1 to be safe and I already have the high side fat on fuel. I do not need that extra 500 RPM for what I do with it.