Why won't my FeatherLite FL-20C weed eater will not stay running when I put it in full choke. What could be wrong?

Have to adjust the high on the carb. should have, 3 screws, 2 that are together is your h for high, and L for low. the one by itself is for idle. when mackine is running, squeeze throttle and adjust the high til it clears up, if it stalls real fast, back counter clockwise while off, and try to restart it, if worse, go the other way. i do mine by 1/4 turns. keep count of turns in case your going the wrong way! hope this helps !

It should run ok after warming up. After starting it, let it run for a minute or so and then try gradually opening the choke. You might try increasing the throttle setting at the same time. After the motor is hot, if you have to have the throttle setting increased in order to keep it running it means the idle setting needs to be increased, usually by turning a screw to keep the fuel valve from closing so much, or that there is a problem with the fuel flow......like a clogged jet or fuel passage in the carb.