That bike does not have your engine in it.

Some may have manuals, most do not. My best guess would be that you have an electrical short, a loose connection that every once in a while loses contact? If is dies abruptly and then starts right up that would be my best guess. The bikes engine is a version of the Honda CG125, there really is not that much to them. Haynes does make a manual for the CG125. It would be helpful for diagnosing. You can also find some basic parts like a CDI and coil etc. for the engine it’s a 167FMM CG version. If you feel you have to have a factory specific manual, then you are painting yourself into a corner, searching for the needle in the haystack. Does it have a kick stand kill switch start with that, a short in that would act the way you described.