I have a kymco super 9 and it wont go any higher then 38mph why is this?

First of all, they are not cheap motors and don't worry about blowing them up. The Kymco lineup is exceptional, I currently have two Kymco models with over 12,000 miles on both, and both of them are derestricted to go 50mph. First of all, there are two different models of the Super 9. A liquid cooled one, and an air cooled one. The air cooled one has no restriction on the cdi. The liquid one has an exposed green wire on the cdi, you want to cut this wire.There is two more derestrictions on this vehicle. One is in the variator, a piece called the boss drive. A restricted one has a shoulder, the derestricted one has no shoulder.. The other is the carburetor main jet, it needs to be replaced to #88 main jet. Check out this site for more information. www.kymcoforum.com