On February 4, 2013, about 0645 eastern standard time, an experimental, amateur-built, SHTTD gyrocopter, N4201S, experienced a total loss of engine power near Montrose, Georgia, after takeoff from the W H 'Bud' Barron Airport (DBN), Dublin, Georgia, about 0630. The pilot subsequently made an off airport forced landing to a field. The certificated flight instructor (CFI)/owner and private pilot sustained minor injuries. The airplane sustained substantial damage to the main rotor blades and the control rods to the rotor mast. The airplane was registered to, and operated by, the CFI under the provisions of 14 Code of Federal Regulations Part 91 as an instructional flight. Visual meteorological conditions prevailed and no flight plan had been filed for the flight destined for the Macon Downtown Airport (MAC), Macon, Georgia. According to the CFI, approximately 5 minutes prior to the accident, during cruise flight, about 2,000 feet above mean sea level, the engine power began to degrade. He increased the power on the engine and subsequently the engine stopped. He assumed control of the gyrocopter and began to maneuver for landing at a radio controlled airplane grass landing area. During the approach, the gyrocopter's main rotor blade impacted powerlines, which severed the control rods to the rotor mast, damaged the rotor blades, and damaged the fiberglass surrounding the cockpit. During the landing, the main landing gear compression strut was damaged, the gyrocopter rolled over, and came to rest on its right side. Initial examination of the engine by a Federal Aviation Administration inspector revealed that the engine could be rotated by hand; however, only through about 30 degrees of arc and then would seize. Photographic documentation of the gyrocopter revealed substantial damage to the main rotor system, horizontal stabilizer, and the fuselage structure. The gyrocopter was equipped with a Subaru EJ 25, 165-hp engine and a Warp Drive, 72-inch propeller. According to maintenance records provided by the owner, the engine had been overhauled approximately 65 flight hours prior to the accident and he had installed it on the gyrocopter on February 16, 2012. During removal of the alternator to facilitate transport to the overhaul facility, a hole was noted in the engine crankcase near the fuel intake system. According to the CFI/owner who was also a mechanic, it appeared that the "No. 2 piston rod had come loose."