The design is flawed because the carburetor just lives to get gunked up no matter what you do. I have tried several Ryobi battery powered trimmers, but they just don't get the job done. I may give it another try, though.

BTW I got that four stroke trimmer when the boys were cutting yards. We'd get these renters who had two foot high grass that had gone to seed, and we'd have to knock it down with the trimmer then run over it with the mower.