Interesting is the rotary engine of Megola shown in the picture, in which does not rotate the crankshaft, but the housing in the wheel. But because when starting with a combustion engine, the wheel speed can not be the same as the engine speed, the crankshaft rotates backward through a suitable planetary gear. There is no exhaust system. The valves are powered directly by the crankshaft.
The supply of fuel-air mixture is made for the side-valve engine centrally from the right side. Since no coupling exists, the engine must be started during cold start by turning the front wheel on the pedestal, warm up some time and be brought to a stop by stalling. After each stop the warm start is made by pushing. One always drives the same gear.