My stihl weedeater does not get enough power?

Try turning the "H" side of the carborator to the right just a little. That is if it has adjustment screws. Some of them now a days don't and can't be adjusted. Also you muffler screen could be clogged. Take you muffler off and clean it and while you're there, look inside your exhaust port and make sure it's fully open,...not full of carbon!!