I think fasttract might be on to something,I ate up a pully last year that destroyed the pully and the spindle.I think it started with the slot for the key being worn enough to allow movement of the pully and I noticed no cut in the middle,took the top cover off and started it up and made a quick diagnosis.Had to buy a new pully and spindle.you said you have new spindles so is there a chance you need to adjust the belt.did you put a new belt on?...russ