Influence of non-commercial fuel supply systems on small engine SI exhaust emissions in relation to European approval regulations.

The development and operation of road infrastructure require machines and equipment driven by low-powered internal combustion engines. In this study, we conducted emission tests on five small spark-ignition engines. We used the most popular commercial design on the market, the Lifan GX 390, with a carburettor power system, and another commercial power unit, the Honda iGX 390, with an innovative power system characterised by an electronically controlled carburettor flap. The remaining three tested constructions were proprietary solutions modernising the design of the Lifan GX 390 engine: one had an electronic injection and ignition system powered by gasoline, whereas the other two had systems powered by alternative fuels. Emission tests were conducted under identical operating conditions on an engine dynamometer complying with European Union guidelines (Regulation 2016/1628/EU). The results of the tests showed that the innovative solutions in most cases reduced CO, CO 2 and hydrocarbon emissions but increased NO x compounds.