In recent years, the free-piston linear engine (FPLE) has attracted increasing interest from researchers worldwide. With the development of computer control technology, internal combustion engine technology, and material science, there have been significant advances in the aspects of FPLE simulation, experimental techniques, as well as systems FPLE control. This paper presents a model of a two-stroke, spark-ignition free-piston engine converted from two small two-stroke engines. It has a bore size of 34 mm and a maximum stroke of 28 mm. The linear engine uses gasoline fuel that is available on the market. The purposes of the research show a model of the starting system, investigation the effects of spark timing, and effective pressure. A premixed air-fuel charge is conducted by a carburetor then it is directly supplied into each cylinder. The spark timing was varied at 1 mm and 2 mm away from the maximum top dead center with the speed starting at 10 Hz. The model successfully ignited with a maximum pressure of 7.5 kg/cm2 at the ignition of 1 mm before top dead center (TDC) and 9.5 kg/cm2 at the ignition of 2 mm before TDC. The research has completed the initial intentions such as a theoretical investigation, calculation, determination of the engine model, and starting mechanism. Preliminary results have confirmed the feasibility of proposing the FPLE model.