The pilot was picking up the airplane for its owner after an annual inspection had been completed. During his preflight inspection he noted that both fuel tank fuel gauges indicated that they were ½ to ¾ full. While he was checking the fuel selector valve the “brittle plastic handle broke off” with the left fuel tank still selected. The pilot called the airplane owner to inform him of the situation and advised that he would add more fuel to the left fuel tank in order to make the anticipated 45-minute flight without switching fuel tanks. He subsequently had 4 gallons of fuel added to the fuel tanks and acquired a small crescent wrench that he planned to use in-lieu of the broken plastic fuel selector handle if necessary. He subsequently departed and climbed the airplane to a cruise altitude of about 6,500 feet. About 20 nautical miles from the destination, he noted that the left fuel tank quantity indication was “bouncing between ¼ and empty” and he decided to change to the right fuel tank for the remainder of the flight. He was subsequently unable to use the crescent wrench to change the fuel selector valve position after several attempts. About 2 nautical miles from the destination airport, while approaching the runway to land, the airplane’s engine lost power completely and the pilot performed a forced landing to a field. The airplane nosed over during the landing and the aft portion of the fuselage left, as well as the wing, were substantially damaged. After the accident, recovery personnel reported that after lifting the airplane upright, they noted fuel staining around the fuel caps of both wing fuel tanks, that the right fuel tank was absent of fuel, and the left fuel tank only contained only a trace amount of fuel. They also operated the fuel selector valve with their own adjustable wrench (the broken fuel selector handle and the crescent wrench used by the pilot could not be located in the wreckage) and found that it operated normally. Based on this information, it is likely that the loss of engine power was due to fuel starvation after the pilot exhausted all usable fuel from the left fuel tank and was unable to select the right fuel tank; or that the pilot had inadvertently moved the fuel selector to an intermediate position in his attempts to use a crescent wrench to adjust the fuel selector valve.