On February 24, 2016, about 1615 eastern standard time, a privately owned and operated Cessna 152, N6449P, was substantially damaged during a forced landing to a road in Pembroke Pines, Florida. The private pilot sustained minor injuries. Visual meteorological conditions prevailed, and no flight plan had been filed for the local flight that originated about 1 hour 5 minutes earlier from North Perry Airport (HWO), Hollywood, Florida. The personal flight was being operated under the provisions of 14 Code of Federal Regulations Part 91.According to the pilot, the engine's valves were adjusted 1 week before the accident in an effort to troubleshoot repeated engine performance issues that would manifest as a rough running engine followed by partial loss of power typically between 10 and 45 minutes into a flight. In advance of the flight, he performed a full preflight check and reported, "everything was normal." The pilot departed and orbited the airport for about 45 minutes, noting no engine discrepancies at the typical elapsed time. He elected to continue flying over the airport in an effort to break-in the piston rings. At about 1 hour 5 minutes into the flight while flying over the southwest corner of the airport, the engine began to run rough. He proceeded to the north side of the airport to sequence for landing on runway 19L, and while operating with the mixture control full rich and the engine at 2,250 rpm, the engine, "totally dropped out", but the oil temperature and pressure were indicating normal. He added power but the engine did not respond and was operating, "pretty much at idle." He declared an emergency with HWO air traffic control tower, and, while on final approach realized he was unable to land on the intended runway. While descending for a forced landing to a road, the left wing contacted a utility pole, and the airplane then impacted the ground which sheared off the nose landing gear. According to a Federal Aviation Administration (FAA) inspector, the accident site was located about .3 nautical mile nearly due north of the approach end of runway 19L. The airplane was moved from the road and secured at HWO, but was not examined before being sold about 2 months after the accident. The individual who purchased the airplane had his mechanic begin troubleshooting to determine the reason for the loss of engine power. His mechanic found an insect nest in the left fuel vent line between the opening and check valve. In a continued effort to troubleshoot the reason for the loss of engine power, the mechanic checked the fuel supply and timing of the magnetos, then removed the engine. The airplane was subsequently relocated to another airport. Examination of the airplane and engine by several FAA airworthiness inspectors several months after the accident revealed all valves gaps were between 0.007 and 0.009 inch, which was within limits per Lycoming Service Instruction No. 1068A. Because a run-out test of the crankshaft flange had not been performed, and the engine had been previously removed from the airframe, an engine run was not performed. Rotation of the propeller revealed crankshaft, camshaft, and valve train continuity. Thumb suction and compression was noted in each cylinder. The magnetos produced spark at all spark plugs and were timed 25 degrees before top dead center (BTDC), while the engine data plate specifies the timing to be 20 degrees BTDC. No defects were noted to the P-leads and terminals, and no defects of the spark plugs were noted, though the Nos. 3 and 4 lower plugs were wet with oil. No blockage of the fuel vent crossover line, or of the air induction and exhaust systems was noted, and the vented type fuel caps functioned normally. Examination of the propeller revealed the tip of one blade was bent aft about 90 degrees and exhibited coarse spanwise scratches on the cambered side of the blade. The opposite blade was bent forward about 90 degrees and exhibited coarse chordwise scratches on the blade back, or non-cambered side of the blade. Gouges were also noted on the leading edge in the area of the blade that was bent forward. Because the engine had been removed, relocated, and then temporarily installed before being examined, there was no fuel found in the carburetor, but the fuel line to the carburetor did contain fuel. A special surface observation taken at HWO about 5 minutes after the accident reported the temperature and dew point to be 28 and 20 degrees Celsius, respectively. According to a FAA Special Airworthiness Information Bulletin CE-09-35, based on the reported temperature and dewpoint about the time of the accident, the conditions were favorable for serious icing at glide engine power settings.