Have a Bolens bl100 weed eater. Can't seem to keep the thing running. It is roughly a year old. Has run just fine up to this point. Put the carb choke on 1... pull the cord 5 times until the engine kicks over and wants to run. Then I move the carb choke on 2 and pull the cord. The engine runs for 10 seconds or less and then dies. Subsequent attempts to get the weed eater to run fail. Help!?