On September 1, 2021, about 1700 central daylight time, an experimental amateur-built Challenger II, N1225G, was substantially damaged when it was involved in an accident near Geneva, Alabama. The commercial pilot received minor injuries. The flight was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, he adjusted the carburetors on the airplane prior to the flight. The pilot departed and stayed in the airport traffic pattern. While approaching to land, the pilot reduced power while turning onto the base leg. As he turned onto the final leg, he attempted to increase power, but the engine “quit.” He made several attempts to restart the engine but was unsuccessful. The airplane lost altitude and collided with the roof of a shed. During the postaccident examination of the engine, it was examined using a borescope, and all four spark plugs were removed. No anomalies were discovered internally within the engine’s cylinders. The carburetors were removed and examined; both were in good operating order. During the examination, a small “cut” was discovered on the fuel line where a clamp held the fuel line to the front carburetor. There was no sign of a leak at the time of examination. The examination also revealed that the rubber boot that held the front carburetor to the manifold was dry rotted. The engine was removed and placed on another airframe for a test run. The engine was started, and a test run was completed successfully with no anomalies noted.