I recently pulled my weedeater out of the shed after a long winter. I gased it up and was able to start it with the full choke on. The problem is as soon as I try and take it out of the full choke position the engine dies. I've ran it for about 5 to 10 minutes in the full choke position but every time I try to move it to half choke or choke off it fires up and runs for a couple of seconds then dies. Any ideas?