On May 17, 2005 at 1013 eastern daylight time, a Rand Robinson Engineering KR-2, N1701L, registered to and operated by a private pilot, collided with an embankment while attempting an emergency landing in Vienna, Georgia. The personal flight operated under the provisions of Title 14 CFR Part 91. Visual meteorological conditions prevailed at the time of the accident and no flight plan was filed. The pilot suffered minor injuries. The airplane was substantially damaged. The flight originated from Cobb County-McCollum Field in Marietta, Georgia on May 17, 2005 at 0930. The flight was enroute to Valdosta, Georgia, at 3,500 feet when the pilot noticed that the engine was losing power and was simultaneously vibrating. The pilot stated that he shut the engine off and decided to make an emergency landing. The pilot first attempted to make it to a crop duster airstrip, but could not and decided to attempt a landing on the highway. The airplane landed on a westerly heading, veered off the highway, hit an embankment and rotated 180-degrees to the left and came to rest on an easterly heading. Examination of the accident site revealed the wreckage was located six miles east of Vienna, Georgia on Georgia Highway 15. Examination of the airplane revealed the right landing gear sheared forward, the left landing gear sheared completely off, and the right wing rear spar fractured. The left wing fuel tank had approximately four gallons of fuel, the right wing fuel tank did not have any visible fuel and the main header fuel tank had approximately 13 gallons of fuel. Examination of the engine revealed the crankshaft was broken just behind the front main bearing before the crankshaft exits the engine and attaches to the propeller. Further examination revealed that the crankshaft had an extension between it and the propeller in order for it to clear the cowling. A review of maintenance records show that a condition inspection was performed by the pilot, who holds a repairman certificate, on March 13, 2005. Maintenance records also show that on May 3, 2005, the propeller extension was found to be out of true and the shaft, propeller and spinner combination was balanced. At the accident site, it was observed that washers were affixed to the back of the propeller spinner and the propeller spinner contained voids in the fiberglass. It was also noted that the crankshaft broke approximately 8.2 hours after the shaft, propeller and spinner combination were balanced.