Can't figure out why the upper shaft is getting very hot around the rubber trigger grip. I can't figure out what is causing this, I've swapped upper shafts with another, but no issues until coincidently, I had the carb dialed in by a shop. The head slips a good bit clockwise on the shaft, but this hasn't ever caused a problem like the hot handle. I believe that during my shaft swap, a bushing or some other type of guide for the shaft may have fallen out near the head and now I'm getting excess friction from the rotation of the shaft. Please help!