Honda Dio rollers

Hi! I have got a honda dio !
i am new to this scooter stuff(earlier had only dirtbikes)
Could you explain me everything about roller replacement, like how small or big rollers can you put, will the belt be sliping if i put some kind of wrong size rollers, what do mixed rollers give?Now i have got 16x13 8.5 g
Thanks

small and big ? i think you mean light and heavy

answer is do not change anything because stock weight rollers are the best for stock scooter , if you change only rollers it most likly run worse