On July 25, 2015, about 1230 eastern daylight time, a Piper PA-28-151, N777EX, operated by a private individual, was substantially damaged during a runway overrun, while landing at Pennridge Airport (CKZ), Perkasie, Pennsylvania. The private pilot was not injured. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the planned flight to Doylestown Airport (DYL), Doylestown, Pennsylvania. The flight originated from South Jersey Regional Airport (VAY), Mount Holly, New Jersey, about 1145.The pilot reported that earlier during the day, he flew from DYL to VAY uneventfully. During his return trip, on approach to DYL, he was unable to slow the airplane below 100 mph as he could not reduce the engine power below 2,000 rpm by manipulating the throttle control. The throttle lever was not jammed, but the engine did not respond when the throttle lever was moved toward a reduced power setting. After five unsuccessful attempts to land at DYL, the pilot diverted to CKZ due to its longer runway. He was still unable to reduce engine rpm below 2,000 by utilizing the throttle control. The pilot was eventually able to slow the airplane below 100 mph during his sixth approach, which was about 30 mph above the desired final approach speed, and he believed that he could stop on the runway with aggressive braking. The airplane touched down on runway 26, a 4,211-foot long asphalt runway, but the pilot was unable to stop before the end of the runway. The airplane subsequently traveled beyond the end of the runway and came to rest upright in a ditch. When asked why he did not reduce the mixture control to slow the airplane, the pilot reported that he was concerned the engine would lose all power. Examination of the wreckage by a Federal Aviation Administration inspector revealed that during the overrun, the nosegear collapsed and the left wing sustained substantial damage. The inspector did not observe any anomalies with the throttle control linkage. The wreckage was reexamined at a recovery facility on September 17, 2015. The throttle linkage was examined and no anomalies were noted. The carburetor was then removed for examination and no anomalies were observed with the butterfly valve. The carburetor was reinstalled for an engine test run. The wings had been removed from the airplane for transport to the recovery facility. The remaining fuselage was secured to a flatbed trailer and fuel was supplied via a 5-gallon container to the right wing side of the fuel selector valve. Once the battery was charged, the engine started on the first attempt and ran continuously. The engine was run to 2,000 rpm and a successful magneto check was performed. The engine was then run to a full power of 2,300 rpm, followed by a power reduction to idle without any anomalies noted. The airplane had been operated for about 11 hours since its most recent annual inspection was completed on May 11, 2015. The pilot reported a total flight experience of 817.3 hours; of which, 717.3 hours were in the same make and model as the accident airplane and 8.3 of those hours were flown during the 90-day period preceding the accident.