On June 6, 2012, about 1015 eastern daylight time, a Piper PA-22-135, N3431A received substantial damage when it impacted the ground and nosed over after it was unable to climb after takeoff from an unimproved field near Bangor, Michigan. The private pilot received serious injuries. The aircraft was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The flight was originating at the time of the accident and was destined for the South Haven Area Regional Airport (LWA), South Haven, Michigan. On the day prior to the accident, June 5, 2012, the pilot was flying the airplane to LWA when he experienced a loss of engine power and executed a forced landing into a field. The airplane was not damaged during the off-airport landing. On the day of the accident, the pilot was attempting to take off from the same field in order to continue to LWA. The pilot reported that after takeoff, the engine stopped producing power and he was attempting to return to the field. The airplane was in a left turn when it struck the ground. The pilot reported that he had added fuel to the right fuel tank and accomplished fuel flow tests on the ground prior to the accident. He stated that the fuel flow from the left tank was not adequate, but flow from the right tank was. He stated that he ran the engine for about 20 minutes on the right tank at high power settings before the attempted flight. A local mechanic who was a witness to the accident reported that the owner enlisted his help to rectify a fuel flow issue. He stated that on the morning of the accident, they added 10 gallons of fuel to the right fuel tank. They then removed the gascolator bowl and timed the fuel flow. The left tank took 7 minutes to flow one gallon of fuel and the right tank took 6 minutes to flow one gallon of fuel. They then performed a run-up to full power on both fuel tanks. He stated that the pilot then attempted to take-off. He said the airplane was slow to clear the ground and gain altitude. It then turned left and descended at which point the witnesses view was obstructed by terrain. A postaccident examination of the airplane after the landing in the field on June 5, 2012, confirmed that the airplane was not damaged. The gascolator screen was found to be almost completely plugged by a flaky shellac type material. The owner reported to the Federal Aviation Administration (FAA) inspector that the airplane had a long history of auto fuel use and that he had been getting the shellac type material from the fuel sumps on the airplane. The inspector and the owner discussed that the owner would get a local mechanic and do a thorough fuel system evaluation and flushing before further flight. The inspector reminded the pilot that there were screens in the fuel tanks, carburetor, and in the belly sump that should be checked and cleaned. A second examination of the airplane after the accident on June 6, 2012 revealed that the gascolator and the carburetor inlet screens were about 50 percent restricted. Neither the pilot nor the mechanics report made mention of having performed a flushing of the fuel system or checking/cleaning of the fuel tank screens in the fuel tanks, carburetor, or gascolator.