To prevent global warming, reducing CO2 emissions is the most important issue, and for this reason, efforts are needed to realize a carbon neutral society. Since hydrogen can be stored and transported, and does not emit carbon dioxide when burned, it has attracted particular attention as a fuel for internal combustion engines in recent years and has been studied in various industrial fields[1]. However, many of these studies have been conducted on commercial and passenger vehicle engines, and there has not yet been sufficient validation on small motorcycle engines. Therefore, in this study, a single cylinder gasoline engine for two-wheeled vehicles was converted into a hydrogen engine with port injection, and the abnormal combustion, which is a problem of hydrogen combustion, was verified. In this report, the parameters affecting the abnormal combustion are summarized based on the experimental results, and the reason why the parameters are a factor of the abnormal combustion generation is examined using the simulation.