On April 10, 1997, about 1820 eastern daylight time a Boeing B75N1, N65467, registered to Avenger Technology Inc., operating as a 14 CFR Part 91 personal flight, crashed after takeoff from River Ranch Airstrip, Lake Wales, Florida. Visual meteorological conditions prevailed and no flight plan was filed. The airplane was destroyed. The commercial pilot sustained minor injuries, and the passenger reported no injuries. The flight was originating at the time of the accident. The pilot stated he was about 150 feet on climbout over the runway when the engine quit developing full power. He made a left crosswind turn in an attempt to enter closed traffic and land. The airspeed started to decrease and the airplane would not maintain altitude. There were no forced landing areas available. He stopped the turn, made a forced landing straight ahead and collided with trees and terrain. The airplane was consumed by postcrash fire. Examination of the engine assembly and accessories revealed no evidence of a precrash mechanical failure or malfunction. The fuel selector valve was found in the off position.