The airplane was about 43 minutes into a cross country flight when the engine began to sputter and lost power. The pilot's attempts to restart the engine were unsuccessful and he chose to make a forced landing to a nearby field. During the approach to land, the left wing struck a tree and the airplane collided with the ground and burst into flames. Post-accident examination of the airplane revealed continuity from the engine power quadrant to the carburetor. The fuel screen of the carburetor was observed free of debris. The needle valve in the carburetor remained attached to the float and was binding in the needle valve seat. The carburetor bowl was free of debris and was undamaged. Weather conditions at the time of the accident were favorable for the formation of carburetor icing. The pilot reported that he did not apply carburetor heat until after the loss of engine power.