Welcome,
hi im in the market of buying a scooter but not sure on what brand.which is the quickest accelerating scooter on the market today in 50 cc catergory, and can they be hottet up?
many thanks 
The answer to that is dependent on where you are. Here in the US the KYMCO Super 9 is among the quicker 50 cc's. Wouldn't know about anywhere else.
As to your question about modifying for better performance. Parts are readily available for the Mineralli engine that is used by several manufacturers, if (and this is a big if!) you are willing to spend a lot of time and money and give up gas mileage and reliability.
Speed cost $$$$. How fast do you want to go?
-old race builders axiom-
