The pilot purchased 30 gallons of aviation gasoline (AVGAS) prior to a local flight. The purchased AVGAS was divided between the left and right fuel tanks. The fuel tanks showed a little over one-half on the right and a little less than one-half on the left. The pilot flew about two tenths of an hour south and then turned north back to the airport. About five minutes after turning north, the engine went to idle. The pilot pulled the carb heat on, activated the boost pump, and the engine returned to normal cruise power. The pilot indicated, "At this point I should have switch to the right tank." The engine ran about one minute then quit completely. The airplane was about 1,500 feet above ground level. The pilot reported that "the changing of the fuel select valve requires the pilot to move the seat back about 18 in[ches] with no control of the aircraft, I thought a controlled forced landing better than an uncontrolled one." The pilot reported that the accident was caused by fuel starvation and that there were no preaccident mechanical failures or malfunctions of the airplane.