On April 13, 2016, about 1230 eastern daylight time, an experimental amateur-built Eaglet motorglider, N5AQ, was substantially damaged when it impact trees shortly after takeoff from Bob Lee Flight Strip (1J6), Deland, Florida. The sport pilot incurred minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight, which was operated under the provisions of Title 14 Code of Federal Regulations Part 91. The flight was originating at the time of the accident.The pilot report that after takeoff, the main reciprocating pusher engine failed about 75 feet above ground level and the secondary electric motor was unable to maintain the motorglider's altitude. The pilot tried to make a 180-degree turn back to the airport, but the motorglider lost altitude and contacted the top of pine trees. The tail of the motorglider caught the top of a tree, preventing it from colliding with the ground. The motorglider was approximately 1 foot off the ground when the pilot unlatched his seatbelt and jumped to the ground. The pilot also reported that he had installed a DLE-170 cubic centimeter, 17 horse power engine and ignition system on the motorglider. He believed that during takeoff, he encountered moderate turbulence and the engine ignition system disconnected. He stated he believed that the certified motorglider was an ultralight and he did not need approval to modify it or keep paperwork, logbooks, and flight logs. The installed engine was designed for model airplanes. The pilot reported that he held a sport pilot certificate and had accrued 130 total hours flight experience, with 40 hours in the same make and model as the motorglider. Examination of the motorglider by an NTSB investigator revealed that the wing leading edges were cracked from tree limb contact. The left elevator was fractured off the hinges and the right elevator leading edge was crushed by contact with tree limbs. The canopy was broken in several pieces. The pilot had removed and transported the engine and ignition system prior to the examination, and they were not available for examination.