The effect of air/fuel composition on the HC emissions for a twin-spark motorcycle gasoline engine: A wide condition range study

•HC emissions of a twin-spark engine were studied over a wide range condition.•The combined simulation approach between GT-Power and ChemKin was presented.•HC amount, intermediates and reaction pathway were studied in motorcycle engine.•The foundation “perfect” oxidation data were added for comparison analysis.•The SOA formation potential in “in-cylinder” environment was investigated.