On October 21, 2010, at 1400 central daylight time, a Piper PA-46-500TP airplane, N767TP, experienced a loss of engine power following takeoff from Johnson County Executive Airport (OJC), Olathe, Kansas. Visual meteorological conditions prevailed at the time of the incident. The pilot was not injured and the airplane received internal engine damage. The test flight was being conducted under the provisions of 14 Code of Federal Regulations Part 91 without a flight plan. The local flight was originating at the time of the incident. The pilot was conducting a post-maintenance test flight. Shortly after takeoff, at an altitude of about 150 to 200 feet above ground level (agl), the airplane experienced a loss of engine power. The pilot moved the power control lever full forward and full aft without any effect on the engine power. The pilot then pulled the Manual Override (MOR) lever at which time the engine power was restored. The pilot was able to return to the airport and land without further incident. The engine experienced an over-temperature event during the recovery. The airframe, engine, fuel control unit, propeller overspeed governor, and related systems were examined. No anomalies were noted that would have precluded normal operation. Fuel samples from the incident airplane were tested and found to be within specifications. The reason for the loss of engine power could not be determined.