May be insufficient fuel flow to keep the carbs bowl full.....If you turn gas on and open the carb bowls bottom drain cock, a continuous steady stream of gas at least a pencil lead thickness must flolw all the time. If not check for restrictions in any sediment bowl or fuel filter or 3 way brass valve etc etc. If you remove the carbs inlet gas line it should flow a steady stream near the size of the lines ID.........
If theres plenty of gas to the carb (filters or sed bowls etc all clear) but the bowl drain dont flow as above, the carbs side circular inlet strainer or the needle valve n seat may have a restriction.
I initially set the carbs idle screw out about 2 turns and the power screw out maybe 1 then get her running and fine tune adjust from there.
Of course, all the above may be good but the carbs internals and power jets and passages may be plugged up???
If choke helps shes just not getting enough gas well duhhhhhhhhhh