On October 8, 1995, at 1200 central daylight time, a Cessna 172N, N738DF, registered to Ginevan Enterprises, Inc. and operated by Ellington Field Aero Club under Title 14 CFR Part 91, sustained substantial damage during a forced landing near Crockett, Texas. Visual meteorological conditions prevailed for the cross country flight and a flight plan was not filed. The private pilot and his passenger received minor injuries. The flight originated from Houston, Texas, approximately 1 hour and 15 minutes before the accident. According to the pilot, he was cruising at 5,500 feet en route to Tyler, Texas. Shortly after passing Kennard, Texas, the engine lost power. The pilot reported activating carburetor heat, moving fuel selector from both to "left or right", and trying to restart the engine. The engine did not start and he proceeded to make a forced landing. Upon touch down in a soft field the airplane nosed over coming to rest in the inverted position. The engine was removed and mounted on another airframe for a test run. Attempts to start the engine were not successful. Examination of the magnetos revealed that the contacts in both magnetos were not opening when the rotor was turned. The contacts were adjusted and the internal timing per manufactures maintenance manual was set. After reinstallation of the magnetos, the engine started and operated normally.