I hope it's not a bad omen! It turns out the mule belt pulley is in two pieces. Its was tack welded together, but they forgot to do the main weld. The dealer , Gravely-Hockessin, dropped what they were doing and got me back on the road. Also on the last lawn of the day, the electric clutch on the Grasshopper burned up. Enclosed is a photo of half the pulley.