I have a 4 stroke troy-bilt string trimmer (weed eater is what we call it in the south) and the head wore out. I got a new "grass gator" brand head from tractor supply, but it doesn't work well. It's the kind that you cut string to length and stick through the holes. They sometimes come out and it gets unbalanced and shakes enough to make my hands hurt/itch. Is there a replacement head that is worth a darn? I prefer the bump to feed type but I'm open to suggestions.