On July 31, 2004, at 0825 mountain daylight time, a Bellanca 14-19-3A, N1251R, piloted by a private pilot, was substantially damaged when it struck mailboxes during landing roll after a forced landing on a road near Estes Park, Colorado. Visual meteorological conditions prevailed at the time of the accident. The personal cross-country flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot, the sole occupant on board, was not injured. The flight originated from Broomfield, Colorado (BJC), at 0809, and was en route to Rawlins, Wyoming (RWL). According to the pilot's accident report, he had just leveled off at his initial cruising altitude of 10,500 feet msl when the engine "sputtered a little bit." He enriched the mixture and the engine "ran fine for approximately five seconds, then quit." Despite remedial action, the pilot was unable to restore engine power. He squawked 7700 on the transponder and transmitted a mayday call on the emergency radio frequency, then made a forced landing on Colorado Highway 7, about 5 miles south of Estes Park. During the landing roll, the left wing struck several mail box posts, crushing the outboard portion of the left wing leading edge. On September 15, 2004, the engine, a Continental IO-470-F (s/n CS-135710-7-F, rated at 260 hp at 2625 rpm), was functionally tested at Beegles Aircraft Service in Greeley, Colorado. During retrieval, both wings were removed. The auxiliary tank had to be used for fuel supply. In addition, the fuel pump was removed from the left wing root and used to pressurize the fuel. The engine started readily. There was reluctance to run the engine higher than 1,300 rpm and 12.5 inches of manifold pressure (MAP) due to the anchoring of the airplane on a trailer. This power setting yielded 5.8 gph. Magneto checks resulted in a 100 rpm drop for each magneto. Air was blown into each wing tank fuel supply line and was felt escaping from the vents. No obstructions were noted.