According to the pilot, he performed a “normal” run-up and proceeded to the departure end of runway 19, a 2,500-foot runway. The pilot stated that he felt rushed because he taxied onto the runway before declaring his intentions. He delayed the announcement of his departure due to another airplane transmitting over the common traffic advisory frequency. After the other pilot’s transmission, he applied full power and began the takeoff roll. He stated that about halfway down the runway, the airplane was not developing as much airspeed as he expected. The Owner’s Manual stated that the rotation speed was 60 mph, however, the pilot stated that he was waiting for 70 mph to rotate. The pilot also noted that he was coming to the end of the runway and decided to abort the takeoff. He pulled back the throttle and applied the brakes but the airplane was not slowing “quickly enough.” The pilot attempted to turn the airplane to the right but was unable to do so. The airplane ran off the end of the runway, traveled down an embankment, and came to rest in a marshy area, substantially damaging the forward section of the fuselage. The pilot noted in his statement that he “forgot to set the flaps properly for takeoff.” The Owner’s Manual stated that the “preferred” flap setting for takeoff was 10 degrees. During a subsequent examination of the wreckage, a Federal Aviation Administration inspector found no preexisting mechanical anomalies with the airplane. The winds reported at an airport 26 miles northeast of the accident location, about the time of the accident, were from 120 degrees at 3 knots.