I have a Echo CS 450 that earlier this year (June) it started shutting off and wouldn't restart. So two weeks ago I was on vacation and tied to cut some wood. Well, it ran for about 20 minutes and went back to doing what it was doing. I took it to a local shop, the place that I bought it from and told them what was going on. Of course they'll have a look and give me a call. Two weeks go by and I call them. "oh yeah" they said, "we finished it yesterday and I was going to call you today." Sure... I pick it up and get home and get ready to start some processing. It gives me a little trouble starting, but it did. I forgot my hearing protection inside, so I set the idling saw on the ground and run inside to get my muffs. I come out and the saw died. I tried and tried but it wouldn't start. I go back to the shop and they ask about my gas. It is brand new, today(with proper Echo mixture)! They take the saw in back and low and behold it fires right up. He said they dumped out my gas and put theirs in. I'm just thinking this is ridicules. I tried to get this saw going but it wasn't working and it fires right up for them?! What is going on? Ok, I will let you know if I have issues", I said. I get home and guess what happens. It doesn't start, now using their gas. I call them back and he says he cannot help me over the phone(no kidding?) but I am bringing it back tomorrow morning. I have had this saw for about 1.5-2 years and have cut 7+ cords of wood. Do I all the sudden not know how to start a saw that I have spent hours next to? Could humidity be playing a part in this, which it shouldn't, right? The last 3 times I've tried to fire it has been when its about 80+ degrees and humid. He claims the gas could be the issue, I have had the exact same gas(no matter how old) in my SRM 225 and have had zero issues. I do understand they probably are different creatures that come from the same mother. Any ideas? I'd like to be able to talk to them and trouble shoot with ideas of what it could be.