Don't worry about the number of miles on your scoot, just ride
...
Some people have bad luck indeed, having to rebuild their engine quite soon - but most people who do nothing more than a simple oil change every now and then will never completely wear out an engine for as long as they ride...
(Most scoots end up crashed, rusted away, or tweaked and modded to the point of breakage by incompetent
morons people
)