Our aim is to carry out a comparative study of the performance of two-stroke and four-stroke internal combustion engines. For this purpose, we have studied the different specificities of two types of single-cylinder internal combustion engine; but to make this study more realistic, we have chosen two engines of equal displacement which are in working order, one a two-stroke single-cylinder internal combustion engine and the other a four-stroke engine, with respective rpm and effective power of 11 [kW] at 8000 [rpm] and 6.72 [kW] at 7000 [rpm]. While many engine designs have focused on the influence of users. We've been looking at the consequences of numerous motor renovation creations on the industrial and transport environment. The aim of this book is to present specific examples of the two-stroke single-cylinder petrol engine for the YAMAHA DT 125 motorcycle compared with the four-stroke single-cylinder internal combustion engine for the HERO Dawn 125 motorcycle, with their differences and similarities.