I HAVE A TROY BILT 4 STROKE STRING TRIMMER THAT I HAVE ONLY USED A HANDFULL OF TIMES. IT IS NOT TUNED FOR 6000 FEET SO, IT CAUSES ME GREIF TO START. I PAID $250 FOR IT. I HAVE SOME EXTRA HEADS AND STRING. I DO THIS FROM A DESKTOP SO, MY RESPONSE MAY BE DELAYED.