1st check the belt tensioner lever hasn't released. This is located under the floor on the left side underneath about where your heal would be. It should be fully rearward and stay there with over centre tension.
Next most likely is the belt has stretched!
To change belt or adjust tensioner, move the lever forward to release belt trension. This moves the front of the cutter deck forward. The belt tension is altered by adjusting the length of the rod which travels under the floor up the left side to the pivot located underneath the very front of the tractor, ahead of the axle. It is attatched to the front of the cutter by a bar about 25cm long.
Duncan, June 2009
