I have an OLD Echo SRM-2501 that's a few CCs bigger than yours. Bought it from a neighbor in 1995 hard starting because his kid had injured it on straight gas. New piston, rings, gaskets, removed spark arrestor, gutted baffles from muffler. 24 years later it still SCREAMS. It has a ton of power.
I'd start with opening muffler, gutting it, and adjusting the carb accordingly.
I run mine on Klotz Super Techiniplate somewhere between 40 and 50 to 1
Picture of the old trimmer for fun.