Cutter runs for approx 10- 20 min and cut off and have to cool down before it starts again.

Hi, have you ever cleaned the unit out? If you have air pressure available, this is the easiest way to do it. Blow all the old dead grass, weeds ect out from the engine area of the Weed eater. If you don't have or have access to a compressor, take the unit to your local garage/service station and ask to use their air, or ask them to blow it out for you. This alone may cure the problem. However the proper mix is critical for proper performance also. If the mix is too lean the unit will over heat. Clean it out, and be sure of the mix ratio. You should be 'good to go'. Good Luck Vern