On March 7, 2015, about 1500 central daylight time, an Ercoupe 415-C airplane, N87EV, impacted terrain during a forced landing following a loss of engine power during a go-around near the St Louis Metro-East Airport/Shafer Field (3K6), St Jacob, Illinois. The private pilot was uninjured. The airplane sustained substantial firewall and wing damage. The airplane was registered to an individual and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a ferry flight. Day visual flight rules conditions prevailed for the flight, which did not operate on a flight plan. The flight originated from the A Paul Vance Fredericktown Regional Airport (H88), near Fredericktown, Missouri, about 1400.The pilot stated in his accident report that he was flying the accident airplane under a ferry permit from H88 to Sackman Field Airport (H49), near Columbia, Illinois. However, due to unsafe runway conditions at H49, 3K6 was chosen as an alternate airport. Upon arrival at 3K6, the pilot executed an aborted landing. He applied engine power and climbed about 150-200 feet. The engine lost power without any "coughing" or warning. At 1358, the recorded weather at the Scott Air Force Base/MidAmerica Airport, near Belleville, Illinois, was: Wind 230 degrees at 2 knots; visibility 10 statute miles; sky condition clear; temperature 18 degrees C; dew point 1 degree C; altimeter 30.13 inches of mercury. A Federal Aviation Administration inspector examined the accident airplane. He observed that the fuel exiting from the header fuel tank was not aviation gasoline. The inspector observed the accident airplane during a subsequent engine run. The engine started, ran rough, and it would not accelerate smoothly when it was fed fuel from the header tank containing fuel from the accident flight. The header tank was drained and fresh aviation gasoline was added to the tank. The engine ran smoothly and accelerated normally.