The pilot stated that he taxied to the end of the runway, conducted a run up, and prepared for takeoff. He said that the airplane developed full power during the initial climb, but began to lose power at approximately 300 feet above ground level. He made a 180-degree turn back towards the runway, but was unable to make it to the airport. He made an off field emergency landing which resulted in substantial damage to the right wing. During an examination of the engine, the carburetor bowl needle was found stuck in the closed position. The pilot did not report any flight control malfunctions or failures that would have precluded normal operation.