In 2016, we began to develop a compact and powerful (about 100hp) engine suitable for ultralight aviation and UAV based on the crankcase and the cylinders of the motorcycle engine "Ural". We have designed crankshaft and rods, increased the piston stroke and the diameter of the cylinder, increased the reliability of the timing drive and installed electronic fuel injection. To increase engine power, we have redesigned the engine fuel supply system, which gain cooling efficiency of the engine and gives a boost effect without the use of a turbo. Details of the fuel supply system will be published after registration of the patent.