On May 2, 1997, about 1415 eastern daylight time, a Thacker Starduster Too SA300, N14525, registered to an individual, nosed over during an aborted takeoff at Lake Wales Airport, Lake Wales, Florida, while on a Title 14 CFR Part 91 personal flight from Lake Wales to Jacksonville, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft received substantial damage and the airline transport-rated pilot was not injured. The flight was originating at the time of the accident. The pilot stated that during takeoff on runway 6, the aircraft started drifting to the right while still at low speed. Application of left rudder did not correct the drift and the right main landing gear tire went off the edge of the runway. The aircraft was traveling at about 30 knots at this time. The aircraft continued to drift right and he aborted the takeoff. After closing the throttle he applied left brake and rudder in an attempt to turn the aircraft back onto the hard surface of the runway. Immediately upon application of the left brake the aircraft nosed over in the soft ground. The pilot stated there was no mechanical malfunctions with the aircraft and he believed that the tail wheel did not lock in the centered detent as he began his takeoff roll.