Hello, I just thought that I would put my two cents in on this. I have had a lot of trouble with Echo trimmers losing power and have thought about changing to another brand of trimmer myself. I think I have a solution that works very well. It has worked for 3 Echo trimmers that we have now. They all 3 run like new now. I have heard of this solution before but I just wanted to put it into detail of how to repair them. First off I would suggest putting a new air filter, spark plug, and even fuel lines on the trimmer. The lines are cheap at Ace hardware for like $1 a foot. You only need a foot. If one of your lines has a hole in it then they will suck air into the line and make it spit and sputter. Second off this is the real reason I'm suggesting a repair is the EXHAUST PORT! This is were my troubles have been. The exhaust port gets carbon build up on it and doesn't let it exhaust out the burned fuel. Even a 25-50% reduction in the port opening can make it not run or run so weak that you feel like you need a new trimmer. To clean the exhaust port you need to take the plastic cover off that covers your exhaust. Then you have to unbolt the exhaust. I know my 280T had an extra mount bolt to the block at the bottom under the muffler too. All you have to do is take the muffler off. Take a flat head screwdriver and clean the port out and chunk the carbon off. ALSO make sure the piston is all the way down out of the way so you don't nick it. I also took my spark plug out and sprayed carburetor cleaner into the two holes from the exhaust and spark plug hole to clean out the cylinder. MAKE SURE that you don't knock carbon into the piston cylinder and then try to pull the cord. The carbon will get crushed up at the top of the head and make the cylinder stick into place. I found this out the hard way. But the carb cleaner cleaned it right out and freed it. Pull your starter cord a couple of times with the plug and muffler off to get any little chunks out of the cylinder. Then put your plug back in and start it up WITHOUT the muffler for 10-30 seconds to blow it all out and clean. You could even spray carb cleaner in there a couple of times with it off. WATCH your eyes so that you don't blow carb cleaner or fuel into your eyes. Just don't look into the port. It's actually neat seeing the piston fire while running through the exhaust port. Then shut it off and put your muffler back on and cover. It should run like a champ again. I use Amsoil Saber synthetic 2 cycle oil mixed about 60 to 1 or even leaner at like 75 to 1. It says you can mix at 100 to 1. But I would rather be safe than sorry. Amsoil gives you more power too because you're burning more fuel than you are oil. Less plug fouls also with less oil. Well I hope this helps someone out. Have a nice day.