[culcune]

I would play with the carb and exhaust and leave the engine alone; that is assuming you want some kind of utility with the scooter. However, it sounds like you got the bike for free or close to free, so perhaps a bore kit might be fun to play with? I had suggested to rich_e on his thread to not bore his wife's scooter out mainly because he bought it brand new for her to learn on, and boring it out might make the engine go south. But a $100 or less scooter might be the perfect Guinea pig to play with. Otherwise, play with the carb and exhaust, or simply look around for a 150cc engine from another discarded scooter as some of TaoTao's scooters came in both 50 and 150 forms.