Bad form on all fronts, especially the "goes 50 or 60" part
To be fair it does have a 70cc kit, 24mm mikuni, estoril exhaust, and tall gearing. not to mention if anything internally was done. It might very well hit 50mph. I built a maxi years back with nearly the same kit (no additional porting), 16mm carb, bi-turbo exhaust, and 18x36 gearing and it would do 53mph with my then 160lb self on it. It sucked off the line but it would get there.