Well, it happened. I was out milling a big red pine log the other day into big wide 15" boards when my Solo 690 might have stuck the piston while making the cut. The chain had gotten pretty dull and the bar hot, so I stopped and sharpened the chain, let the saw cool off for 10-15 mins and resumed cutting. I hadn't gotten very far when the saw abruptly quite in the cut. I instantly thought: "Oh no!" and when I pulled the starting cord it didn't budge. I thought that was that, but later the engine did turn over (cooled off?), and yesterday I started it and it seemed to run okay. So now I wonder what the heck to do. Today I'll take off the covers and see if I can find any air leaks. Also will make sure it is "4-stroking" when operating. I rather think it was, yet when the chain was dull it seemed to be running awfully fast. But of course now I'm questioning everything. I use a 40:1 mix of semi-synthetic aircooled 2-stroke engine oil (Citgo) with premium gas and I always shake the gas can. Any tips or advice on what to do? I'm trying to convince myself that it really didn't stick and I just forgot to press the compression release when I first tried it, but that's probably wishful thinking. More likely I had a minor seizure that un-seized itself when the saw cooled down. I know I should pull the muffler and look at the piston for scoring, but since one muffler screw is stripped and JB welded in, I'd rather not do that. Thanks PS: Why don't chainsaws have auto shutdown when they get too hot?