The pilot attempted the takeoff with the airplane loaded 238 pounds over the maximum gross weight of 3,833 pounds, with the center of gravity (cg) 3.3 inches aft of the aft cg limit. During the takeoff roll, the nose of the airplane lifted 10 knots prior to the recommended rotation speed for a no-flap takeoff, and witnesses described the airplane in an unstable "pitch-up" attitude before it settled back on the runway and overran the departure end, struck a ditch, and came to rest with substantial damage to the left wing and horizontal stabilizer. The pilot reported he had 1.8 hours of flight experience in the accident airplane make and model, and that there were no mechanical malfunctions with the airplane that would have precluded normal operation.