On June 10, 1996, at 2020 central daylight time, a Piper PA-25-235, N7289Z, sustained substantial damage during a forced landing near Waterville, Kansas. The pilot told authorities that the engine quit in cruise flight and he initiated a forced landing. The landing was in an open field with high vegetation. The airplane nosed over. The pilot reported no injuries. The 14 CFR Part 91 positioning flight was being conducted in visual meteorological conditions. No flight plan was on file. The flight departed Macon, Missouri, time unknown with the intended destination of Beloit, Kansas. After the accident, the airplane was righted for examination. No fuel remained in the fuel tank. It was noted that a fuel leak at the gascolator was present when the fuel valve was opened. The pilot stated that it was his practice to turn off the valve prior to leaving the cockpit after landing and to turn on the valve after entering the cockpit prior to starting the engine. A fuel leak from the gascolator cannot be observed by the pilot when he is in the cockpit. Four gallons of aviation fuel were added to the fuel tank. The engine was started and ran at idle and full power. Magneto operational checks performed within specifications.