Internal combustion engines (ICEs) remain widely used in automotive transportation for their high energy storage system efficiency and economic benefits. The 4-stroke engine has dominated all other forms to date, because the Otto cycle is relatively simple to understand. However, the significant benefits such as less pumping work and friction, lighter construction of 2-stroke engine, are attractive for applications that prioritize the simplicity and power density as well as meet the emission regulations. The disadvantages of the 2-stroke engine are mainly caused by the lack of sufficient scavenging process. Also, the overlap of the intake and exhaust phases results in charge short-circuiting, more fuel consumption and high unburned hydrocarbon emissions. For these reasons, it is difficult for 2-stroke engines to achieve stoichiometric combustion, making them incompatible with three-way catalyst to control emissions. The residual exhaust gas in the cylinder makes the spark ignition application leads to incomplete combustion and a higher coefficient of variation. Hence, it is imperative to investigate the effect of spark ignition strategies (ignition position, ignition timing conditions) on a portable small 2-stroke engine with complex in-cylinder gas flow distribution. In this study, we discussed the effect of spark ignition strategies on a small 2-stroke engine. In-cylinder combustion characteristics, emission characteristics and flame propagation process were observed by an optical 2-stroke engine with loop-scavenging. Additionally, in terms of fuel properties, gasoline, dimethyl carbonate/gasoline blend fuel and primary reference fuel are used to investigate the influence of ignition method on knock intensity with different octane numbers. To analyze the effect of fuel properties on combustion characteristics, the computational fluid dynamic (CFD) simulation using CONVERGE were conducted to predict the flame propagations. Through the experimental and CFD results, the potential for combustion improvement on 2-stroke spark ignition engine was evaluated by the optimization of ignition strategies.