On March 21, 2015, about 0920 mountain standard time, an experimental amateur built Vans RV-6A, N811KM, was substantially damaged during a forced landing following a loss of engine power during takeoff from the Ruby Star Airpark (14AZ), Green Valley, Arizona. The airplane was registered to Sunset Enterprises LLC and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The private pilot and his pilot rated passenger sustained minor injuries. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight. The cross-country flight was originating at the time of the accident with an intended destination of Tucson, Arizona.In a written statement, the pilot reported that after takeoff from runway 6, at an altitude of about 300 feet above ground level, the engine lost power and he initiated a right turn toward the airport. Subsequently the airplane impacted terrain and trees about 100 feet from the runway and nosed over. Examination of the airplane by local law enforcement revealed that both wings and fuselage were structurally damaged. The wreckage was recovered to a secure location for further examination. Examination of the recovered airframe and engine revealed that the engine remained attached to the firewall via all its mounts. The carburetor was intact and disassembled. All internal components of the carburetor were intact. All six spark plugs were removed and the propeller was rotated by hand. Thumb compression was obtained on all cylinders. Throttle, mixture, and carburetor heat control continuity was established from the cockpit controls to the engine. All of the engine belts were intact and undamaged. The engine was not equipped with an engine driven fuel pump. Battery power was applied to the airframe and the left and right fuel pump would not function. The positive power wire for the right fuel pump was disconnected from a quick disconnect terminal connector, which was enclosed within a plastic tube with electrical tape on one end. The positive power wire for the left fuel pump was connected to an insulated quick-disconnect terminal. The terminal halves were partially disconnected, enough where the inner metal terminals were disconnected. No additional anomalies were found during the examination of the airframe and engine that would have precluded normal operation. The airframe and engine logbook records were not located.