Thanks for the advice. I think I know what went wrong. One of the bolts that holds the muffler on vibrated loose leaving the muffler to slide down on one side and partially block the exhaust port. i think I'll try the meteor piston first as you suggest. How do I know if the cylinder is good and how would I clean it if needed?
#1, remove muffler and take some pics of the cylinder and piston through the exhaust port. Piston all the way up, piston half way up, and piston all the way down.
#2, do a compression test. If it's below 130ish, you need new rings at a minimum. Remove cylinder and look at it and the piston for transfer or scoring. If there's transfer, most of the time the cylinder can be saved by applying muriatic acid with a qtip. Or by sanding with a drill. There's a stickied thread by mastermind at the top of the chainsaw section. If the piston is marked up from scoring, it'll need replaced. But like I said, usually, the cylinder can be saved.
Just a heads up, we like pics. Learn how to post pics and help will be everywhere lol