Do 49cc mopeds and pocket bikes have the same engine parts?
Usually No ! That’s the way manufacturers make their money, even an engine manufactured by the same company can have different parts. The only way to be sure is find out specifications and then you need to know how to use “specialist measuring equipment” For example a piston might look the same even have the same measurement (diameter for the bore) but the ring landings or the gudgeon pin might be positioned differently. I suggest a lesson or three from an engineering shop could help but you will find it’s a lot of work and a very “specialized” field of work and experience.
