Small Engines (Lawn Mowers, etc.): weed wacker issues, weed wacker, weedwacker

Question
have 3 different brands that have same issue: When you pull on the cord to start the gas machine, the cord seems to stop suddenly as though caught on something, but inspection of cord shows no issues, even inside. It seems that the issue is not there but where and how do I fix it?

Answer
are these units clutch driven?  If they are direct drive when you go to start them are they on the ground?  perhaps it is the cutting head that is striking the ground giving you the symptom you describe.

Try hand holding the weedwacker-making sure the cutting portion doesnt hit the ground, and starting it, do you have the same symptoms?