I have pretty much OEM 03 S9 LC, has pod airfilter, larger carb jets, and some CVT tuning. It runs over 50mph/ 80km on speedo, which is probably 5 to 7mph high.
I sold 03 S9 LC with pod airfilter, Malossi variator, Dr Pulley sliders, Malossi torque spring, Malossi torque driver, Tecnigas NextR pipe, and I think can hit true 60mph from time to time, depending upon wind direction, slope of road. Note: doesn't have 70cc kit, still 49cc. Cheers