dio 18 is the best 50 scooter ever made ( thats %100 stock , not modified )
first mode on dio is to change variator pully ( and not cylinder )
.. best varios ( like every other part )are only made for piaggio and jog so for best results to fit those into your dio and leave everything else stock , i seen 80kph on GPS out of %100 stock 50cc with just a pully ( stock was 62kph on GPS )