RE: Is the engine new or old?
Don't know if there is a way to tell if it ran more than once, maybe how much carbon in the header?
The thing about the carb setting is for us where I live 2 1/2 turn out is were it should be after breakin is complete.
since it is set at factory settings maybe thats how they ran it the one time without touching the needle, I guess it all comes down to trusting who ever sold it to you.
Dan.