On January 9, 2016, about 1600 eastern standard time, an experimental amateur-built Avid Mark IV, N72MT, was substantially damaged following a forced landing after takeoff from Florida Flying Gators Ultralight Flightpark (3FD4), Minneola, Florida. The sport pilot was seriously injured. The airplane was privately owned and operated under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Day, visual meteorological conditions prevailed, and no flight plan was filed. The local flight was originating at the time of the accident.The pilot reported that, after takeoff, he turned onto the crosswind leg of the traffic pattern. He performed a steep turn after takeoff to avoid horses off the end of the runway. He then noticed the smell of "burning wires" and "may have seen a wisp of smoke." At 300 feet above the ground, and while still climbing, the engine "sputtered, then died." He made a radio call that he was returning to the runway. The left wing then stalled and the airplane rolled inverted and entered a downward spiral. The airplane collided with two trees during the descent before colliding with the terrain. The airplane came to rest in a grassy area, inverted. Inspectors with the Federal Aviation Administration (FAA) responded to the accident site and examined the wreckage. They observed structural damage to fuselage, empennage, and both wings. An FAA airworthiness inspector examined the engine and found no evidence of a mechanical failure or malfunction. There were no arcing or burn signatures on the engine's electrical wiring or connectors. A postaccident test run of the engine could not be performed due to impact damage. The pilot received his sport pilot certificate on September 2, 2015, after taking a two-week training course. He reported 120 hours of total flight time, including 100 hours as pilot-in-command. He also reported 65 hours in the accident airplane make and model, all as pilot-in-command. He stated that, after the accident, he took additional lessons with his original flight instructor to practice emergency procedures, stalls, and stall recovery.