Ducati manufactures the most fastest bike in the world! Once I was a person who was riding the same! Bike was just going like a rocket! Well, it is also possible to make bike faster! Check this one https://rideapart.com/articles/best-ways-make-motorcycle-faster
According to the site below, the fastest bike is the Kawasaki Ninja H2R which can hit over 249 MPH.
Yes! It is possible to modify pocket bike! Moreover, you can do that in your home! You can modify your by doing some simple things such as fixing stickers, LEDs, and more. You can also visit https://www.truworthhomes.com/blog/how-to-modify-a-bike-at-home.html for more tips.