Manual for Homelite TRIM N' EDGE UT20772 string trimmer with curved shaft:
Eng starts but will not accelerate -> need carb service (thanks for the help there buddy!)
Eng starts but will only run at hi speed at half choke -> turn mixture needle (funny shaped plastic with small slot - located beside projecting rod at bottom fromt of the carb) C-CWise 1/16 turn. (Note there are stops on this that only allow about 1/4 turn total)
Eng does not reach hi speed and smokes -> (1) fuel stale or wrong mix issue (s/be 2.6 oz/US gal) (2)clean air filter (3) turn mixture needle CWise 1/16 turn (4) spark arrest screen dirty (inside muffler), get serviced
Runs OK, will not idle -> screw in idle screw (one with tapered tip that moves plate attached to throttle cable - near the primer bulb)
Hope this helps - I'm going to try to fix mine now too.
HandyAndy, September 2009