I have a Weedeater Brand straight shaft string trimmer i have a question about ? It is several years old but starts up every time with a few pulls. My question is when I start it i go threw the regular priming the bulb and moving the carb lever to full choke, after a couple pulls i go to half choke and it starts. However after I run it for a couple minutes I move the lever to run and it always starts to dog down the motor and you cannot throttle it up for anything and it will die. Okay, if I leave it on half choke instead of moving it to run it will run all day no problem , so most of the time I just leave it on half choke. However I do not get it to rev up very much when I am running on half choke. I have cleaned the filter and sprayed the carb with cleaner but it still does the same thing.