[bandito2]

You shouldn't just guess at the oil level. For most scooters, the proper way to check is with the scooter on the center stand on level ground. At the oil fill, the cap often has the dip stick integrated. the level is checked by putting the cap into place, but not screwed in.

Too much oil can give problems with excess being sucked up into the air cleaner. (that is if hoses are in place and crankcase venting goes to the air box)

Head gasket should still be good on a new scoot; so not likely, but not impossible either. Who knows what kinds of unseen defects may make their way into something during manufacture... It does happen, but I have doubts about that being the case here.