On July 11, 2016, about 1250 eastern daylight time, an experimental exhibition Tumbling Goose LLC, 12S, N867TG, was substantially damaged during a forced landing following a loss of engine power while approaching Tangerine Airport (FL97), Zellwood, Florida. The pilot incurred serious injuries. Visual meteorological conditions prevailed and no flight plan was filed for the personal, local flight. The airplane was operated under the provisions of 14 Code of Federal Regulations Part 91.According to the pilot, this was his second flight in the newly manufactured experimental exhibition airplane. His first flight was earlier that morning, and he flew for approximately 30 minutes over the airport to get familiar with the new airplane. The flight was uneventful and he made two practice approaches before landing and debriefing with the airplane builders on the handling characteristics of the airplane. Several hours later, the pilot departed again to perform aerobatics in the airplane with a sufficient amount of fuel for the planned flight. About 1 hour into the flight, while flying at 4,000 feet above ground level (agl), the pilot reduced the engine power in order to descend towards the airport for landing. At 2,000 feet agl, the pilot advanced the throttle with no response from the engine. He looked at the engine monitor and discerned that the engine had lost total power, though the propeller continued to rotate. The pilot turned the fuel boost pump on and noticed positive fuel pressure, and he moved the mixture and throttle controls with no effect on the engine. The pilot then toggled the spring loaded fuel primer switch, the engine restarted, and appeared to go to full power. Once the pilot released the fuel primer switch, the engine again ceased producing power. The airplane was now over the airport, so the pilot set up for a landing on the grass runway. The pilot noticed he was still high and flying "very fast" for landing, so he performed a go-around maneuver by using the primer switch to start the engine and fly around the traffic pattern to set up for another landing. On the next landing approach, the pilot slowed the airplane, and once over the runway, he attempted to flare for landing. The airplane continued to fly about 10 feet agl for the length of the runway. The pilot tried to perform another go-around by toggling the fuel primer switch again. The engine restarted, but lost total power shortly after and did not restart. At the time, the airplane was about 200 feet agl. The pilot then attempted to perform a forced landing to a clearing. The airplane was "too low and slow," and impacted trees and terrain prior to the clearing. According to the Federal Aviation Administration (FAA) the single seat, bi-wing, fixed landing gear, experimental airplane, serial number 353, was manufactured in 2016. It was powered by a Barrett Performance, Vedeneyev M14P, 430 horsepower engine, equipped with a 3-blade MT propeller. The airplane's most recent100-hour inspection was completed on March 16, 2016, and it had accumulated 7 hours of total hours of flight time since that date. The airplane was equipped with an engine primer system for starting purposes, which injected an unregulated fuel supply directly from the fuel boost pump into the supercharger, which bypassed the fuel/air servo controller. Examination of the wreckage by the Federal Aviation Administration inspector revealed that it came to rest upright with the nose and engine buried in the ground. Both wings were substantially damaged, and the tail section fractured just behind the pilot's seat. The fuselage was crushed by the impact with the tree. The engine controls all appeared to be intact from the cockpit to the engine. The fuel system was clear of blockages up to the fuel servo. Operation of the fuel servo could not be confirmed due to impact damage. The induction system was free of blockages. The original ignition system had been replaced after the engine's most recent overhaul with an experimental electronic system, and the original carburetor was replaced with an experimental fuel injection system, also after the last overhaul.