The Experimental airplane was substantially damaged during an attempted landing on a private airfield at about 1745 Eastern time; the Private pilot was seriously injured. According to the pilot, he performed a touch-and-go landing at his private airfield and, during the climbout, observed fuel venting from the right wing. He then switched the fuel tank selector from the left tank to the right tank. He then flew the downwind leg of the traffic pattern. Subsequently, while turning onto the base leg, the engine lost power. The pilot was able to restart the engine; however, it lost power again shortly after the restart. The pilot then set up for a forced landing, during which the airplane impacted trees. The pilot later told the NTSB that he had not secured the selector into the right tank detent, effectively turning the fuel off.