The airplane was damaged when it collided with rough, soft terrain and the gear collapsed during a forced landing on a dirt road. The forced landing was executed following a power loss due to fuel exhaustion while the airplane was descending to land at its destination. No fuel was found in the system following the accident and no fuel stains were found on the airplane. The PIC stated that the estimated time en route had extended from two hours and forty-five minutes to three hours and thirty-six minutes, but that the fuel gauges read empty and one quarter full when he arrived in the area of his destination. The pilot stated that he thought that he had a hanging main gear door and it created a low pressure area near the fuel tank vents which pressurized the fuel tanks and caused siphoning. The fuel consumption rate for the outbound flight had been 12.3 GPH and the return flight fuel consumption was 15.8 GPH at, according to the pilot, the same power settings.