On September 24, 2020, about 1430 mountain daylight time, a Kitfox Speedster, N525PP, was substantially damaged when it was involved in an accident near Leadville, Colorado. The private pilot sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, he filled both fuel tanks before the prefight at the Lake County Airport (LXV), Leadville, Colorado. The pilot taxied to runway 34 and began the takeoff. The pilot stated that although the initial engine runup was normal, it seemed like the airplane used more runway than expected during the takeoff roll. The airplane became airborne, settled back onto the runway surface, and became airborne again. The pilot stated that the airplane did not climb normally at the departure end of the runway and the engine rpm was in the low 4,000s. The airplane descended despite the throttle being in the full power position. The pilot contemplated a turn back to the airport, but instead decided to land the airplane straight ahead into a field containing short pine trees. The right wing struck a small tree, and the airplane came to rest on the ground against another tree. The right wing and empennage were bent and twisted. Postaccident examination of the airplane and engine revealed a plugged carburetor breather tube that was not impact related damage. The pilot reported that he plugged the tube with a screw two days before the accident. He mistakenly plugged the tube, thinking that it was it was a primer line.