Experimental studies of the JDC (Jet Dispersed Combustion) method to stimulate burning in SI piston engines are presented. The principle of the method is to disperse combustion gases originated from the homogeneous charge flame kernel throughout whole combustion chamber by means of the gas jet intoduced in the combustion chamber from outside. The investigations were performed with the use of a constant volume bomb, a single compression machine and a single cylinder research engine. The wide range of system parameters were studied with the special emphasis on lean mixture burning. It has been concluded that the JDC method might be the efficient way to stimulate and to control lean mixture burning in the quiescent and turbulent environment. The method could be also used to direct the flame propagation toward the required region of the chamber.