The flight instructor and private pilot were completing a circle to land maneuver on an instrument approach after breaking out of overcast clouds at approximately 1,300 feet above ground level (AGL). While on the circle to land downwind leg at approximately 1,100 feet AGL the pilot turned on the electric boost pump, switched the fuel tank selector valve from the right to left tank, and observed positive fuel pressure. The engine then began to sputter and the flight instructor went to full power with the throttle and switched back to the right tank. The engine sounded like it might rev up but then quit completely. The flight instructor took control and executed an engine out forced landing on airport property short of the runway. There was substantial damage to the spars of both wings and all three landing gear. Both pilots received minor injuries during the impact sequences, and both were able to exit the airplane unassisted. Both pilots reported that there was adequate fuel in both tanks. An examination of the airplane's engine and other systems showed no anomalies. The facility that refueled the airplane before the flight reported that post accident fuel quality checks of the tank farm and the refueler were nominal. The airplane was not equipped with shoulder harnesses. Because of the airplane’s year of manufacture shoulder harness installation was not required. The flight instructor said the injuries to his face would have been lessened if he had been wearing a shoulder harness. Both pilots said their injuries would have been much worse if they had hit the ground harder than they did.