On February 28, 2016, at 1337 eastern standard time, N187SF, Czech Aircraft Works SPOL SRO - SportsCruiser, made a forced landing after a total loss of engine power while on takeoff from DeKalb-Peachtree Airport (PDK), Atlanta, Georgia. The airplane sustained substantial damage, but the private pilot/owner was not injured. Visual meteorological conditions existed at the time of the accident and no flight plan was filed for the flight that was being conducted as a 14 Code of Federal Regulations Part 91 personal flight. The flight was originating at the time of the accident. The pilot stated that this was his first flight of the day. He conducted a thorough preflight inspection of the airplane before he started the engine. He then let the engine warm up to normal operating temperature before taxing to the runway. The pilot said he performed an engine run-up and everything was normal. Both fuel tanks were full with about 15 gallons of auto-gas, and the fuel selector was on the left tank. The fuel pump was "on." During the takeoff from runway 21R, the engine lost power. He switched fuel tanks, but the engine did not re-start. The pilot declared an emergency and attempted to land on runway 3R, but landed about 300 ft southeast of the runway on grass. The landing gear collapsed on landing and the airplane slid and spun 180° before it came to rest. The airplane was equipped with a Dynon Skyview display. Engine performance data downloaded from the unit revealed an interruption in fuel flow to the engine during the short flight, about 12.5 minutes after the data recording began, and about 2 minutes before the data recording ceased. A postaccident examination of the airplane and engine revealed the fuselage, both wings, the firewall, and an engine mount were substantially damaged. The Rotax 912 ULS engine remained attached to the airframe and two of the three propeller blades were broken off at the hub. Both carburetors were displaced from their respective sockets and the gascolator bowl was shifted from its mounting bracket. The float bowls were removed from each carburetor and inspected. A small amount of fuel was observed in each bowl along with a small amount of contamination that was consistent with a small particle of fuel line. No mechanical anomalies were noted with either carburetor and the float bowls were re-installed on the engine. The spark plugs were removed from the engine and a continuity and compression check were completed via manual rotation of the propeller. No mechanical issues were noted. The engine was then prepped to be test run, which involved cutting the remaining propeller blade and removing the fuel pump inlet line from the firewall and placing it in a fuel container with fresh fuel. The engine was started and run to 5,700 RPM (5,800 RPM was max). Fuel pressure was 5.8 PSI, which is in the normal pressure range. The engine ran continuously for several minutes without hesitation. No mechanical deficiencies were observed with the engine that would have precluded normal operation at the time of impact. Examination of the airplane's fuel system revealed that the airplane did not have a mandatory fuel return line installed as per the Rotax 912ULS installation instructions. The fuel return line was made mandatory via an amendment to the installation manual on August 1, 2012. The manual stated on page 3, section 73-00-00, subsection 1.1) Description of system – Return Line, "NOTE: The return line prevents malfunctions caused by the formation of vapor lock." Additionally, page 6, Section 73-00-00, subsection 1.3 of the manual stated, "Requirements of the fuel system – Fuel return line, NOTICE: The installation of a fuel return line is mandatory. If the fuel distributor piece with regulator from Rotax is not available, the fuel pressure must be regulated by a restriction in the fuel return line, which ensures that the fuel pressure is under all operation condition within the operating limits specified by Rotax." No fuel return line or restrictor regulator was installed on this airplane as per the Rotax installation instructions. The accident engine was manufactured in January 2012 and was not the original engine installed on the airplane. A review of maintenance logs revealed the engine was installed on the accident airplane by a repair station in December 2013. The pilot/owner purchased the airplane with the new Rotax 912ULS engine already installed in 2014. He was unaware that the mandatory fuel return line was not installed. The Airframe Maintenance Manual (AMM) depicted the airplane's fuel system design layout with a fuel return line installed. However, the accident airplane was manufactured in 2008 and based on the information provided by the airframe manufacturer, no Czech SportCruiser airplane manufactured prior to 2010 had a fuel return line installed. The fuel line was only made mandatory by the engine manufacturer, Rotax, if their Rotax 912ULS engine was installed after August 1, 2012. The airframe manufacturer made the fuel return line standard in September 2010 as the design modification no. S - K - 0084 and a change to the AMM Revision 6, for the SportCruiser in January 2011. According to the airframe manufacturer, 94 airplanes were manufactured for the US market without a fuel return line. Prior to the design modification, there were no reports of any engine problems or shutdowns. The pilot held a private pilot certificate for airplane single-engine land and instrument airplane. His last FAA third-class medical was issued on July 24, 2014. The pilot reported a total of 1,117 flight hours, of which, 56 hours were in the same make/model as the accident airplane. At 1255, the weather reported at the airport was visibility 10 miles, wind 210° at 10 knots gusting to 20 knots, and clear skies.