On March 5, 2006, at 1645 eastern standard time, an experimental Rans S-6ES Coyote II, N5196W, registered to and operated by a private owner, as a 14 CFR Part 91 instructional flight, lost engine power, made a forced landing, and nosed over inverted two miles north of Cartersville Airport, Cartersville, Georgia. Visual meteorological conditions prevailed and no flight plan was filed. The airplane was substantially damaged. The commercial pilot/ flight instructor (CFI) reported minor injuries, and the student pilot was not injured. The flight was originating from Cartersville Airport at the time of the accident. The CFI and student pilot were practicing take off training, pattern work, and approach to landing instruction. The CFI stated that after making a "touch and go", the engine began to "sputter" and was losing power. The airplane was 300 to 400 feet above the ground and about two thirds down runway-01.The CFI took control of the airplane and leveled it out in hopes that the engine would regain power. The engine stopped and the CFI made a forced landing in a field adjacent to the airport. The airplane collided with a ditch on touch down and nosed over inverted. The registered owner of the airplane stated, "The engine assembly was removed from the airframe and examined. The top spark plugs were removed. The electrodes were normal as depicted in the Rotax Maintenance Manual, and the proper gap was set. The oil and fuel lines were not breached. A visual fuel sample was taken and no contaminants were noted. The fuel system was intact and full of fuel. The three in line fuel filters were free of contaminants. The carburetors were inspected and no contaminants were noted. The electrical system was examined. A functional check of the electrical coils and lighting coils was completed. No anomalies were noted. Manually turning the engine checked the gearbox. The rotary valves were functional and compression appeared normal with rotation of the engine by hand. The engine head was removed and no damage was noted to the pistons, sleeves or rings. No determination was made pertaining to the loss of engine power."