The pilot was also the owner of the fixed tri-wing, amateur-built aircraft. After returning from a local flight, he entered the traffic pattern. He flew a large pattern to maintain spacing behind a Cessna 150. After making a low approach, he positioned himself behind the other aircraft in another large pattern. While descending on final approach, the engine coughed and then quit. The throttle was pumped, the engine restarted momentarily, then lost power again and could not be restored. The pilot was unable to reach the runway. The plane was landed in an area of brush and briars about 1000 ft from the runway and was substantially damaged. An investigation revealed no precrash, mechanical failures. Some fuel was remaining in the fuel tank. However, the fuel tank was of the owner's design. With the aircraft in a straight and level flight attitude, there was 3/4 inch of fuel. But when it was tilted to about 10 degrees nose down, the fuel ran forward leaving no fuel pickup point.