hello, i recently purchased a troybilt curved shaft 4 cycle string trimmer from Lowe's. i also bought the grass gator 4 line load n cut trim attachment. i installed the grass gator attachment and cut for about 10 minutes before the machine broke. it seemed to sputter and shake w/ the gator attachment whenever the trim hit thicker grass or against the fence. it was like it was struggling to get back up to speed. once it caught up, then it would spin fine. well, after 10 minutes, the spool quit spinning. when i took the boom attachment apart, the shaft inside was broken off so that's why the spool quit spinning. we took it back to Lowe's and they gave us a new boom for the cutting end. well, it still seems to have the same type of problem w/ the grass gator attachment. i'm afraid to keep running it in fear that it will do the same thing. should i go to a 2 cycle engine, maybe a straight shaft, or get rid of the grass gator?? any advice would be greatly appreciated. thanks!