My Echo weedeater suddenly stopped, mid-run. Pull cord would not budge the engine at all. I was using the proper Red Armor fuel, and it had been running great, with a new carb, for a few hours. I surmised it had over-heated and piston seized. Tried repeatedly, definitely would not budge. I filled the cylinder with Red Armor fuel in hopes of loosening the seize, removed pull-cord cover and shroud, and wiggled the gadget on end of drive shaft, that engages with pull cord. At first it would barely budge, but within a minute, had it turning freely in both directions. Reassembled and it started right up! Seems to run fine but have only used for a few seconds. Hopefully it is undamaged. #diy source