Tumbler stopped rotating

I followed the instructions to remove the front section then I completely removed the tumbler. I placed the belt in the groove making sure it stayed flat, pulled it tight and secured it with a zip tie. Put the tumbler back in with the looped part of the belt facing the motor, then I put the front section back together.Next from the rear access panel I held the belt tight with my left hand and cut the zip tie with my right . Still keeping the belt tight I looped it around the motor and spring tension retainer. From start to finish it took about forty minutes.