Hi all. I have a 3 year-old troy-bilt gas trimmer, model # TB70SS, 2-Cycle. It has been working fine until yesterday. It starts and idles but will not accelerate to cutting speed, it stalls out instead. I've already added clean fresh gas with the proper 40-1 oil mixture, cleaned the sparkplug, and cleaned the spark arrestor screen. Somehow it had been running without an air cleaner element, and with no exhaust hood diverter or exhaust hood - the parts list says it should have these 3 parts.

Anyone have any ideas about why the trimmer now stalls out each time the trigger is squeezed? A dirty carburetor? I added Sta-bil to the fuel tank last fall.

thanks very much.