Fuel filter or high speed circuit in the carb. The fuel filter is doubtful but I would start there 'cause it's easy and worth eliminating as a cause. Pull it out of the tank and spray with carb cleaner. If that doesn't work and you have mixture adjustments on the carb I would give them 1 turn in, 2 turns out and 1 turn back in to arrive at your starting point. That may knock some gum or trash loose and get you on your way. If it's still not working then remove the carb, dissasemble enough to get to the internals and blast with cleaner, you may want to run some tag wire through small passageways. (Tag wire is what you get from the middle of a bread bag twist tie)

Hey,

My Echo is doing the same thing and we replaced the Carb...still stalls an can't reach higher RPM..

You clean the exhaust screen, took the muffler off the clean out all the carbon?

Muffler and screen are clean..could it be the little white fuel check valve? Never replaced it in 5 years..

Another suggestion: My Echo has a vent tube that goes into the fuel tank. It has a white plastic end that I believe allows air to get into the tank - to prevent a vacuum. I accidentally pulled mine out when pulling the start cord. I re-inserted it and got it too far into the fuel tank. It wouldn't run properly. I assume I got it into the fuel and prevented air flow from the outside. Pulled it out a bit and it ran okay.

Mine did this right out of the box. Its never ran right and now my one year is up. thought it was something simple but i found out a lot of people having this problem and the dealer told me it cant be fixed. Used this piece of junk twice.

Echos are excellent trimmers , 90 % of problems are due to ethanol fuel and operators who do not maintain their equipment properly .