Can anyone direct me to a website or to someone who races ATV's with CVT transmissions that has modified the inner workings and/or springs to increase the speed of their ATV?

I have two 2006 CanAm DS250's that I'd like to go faster than the 40/45-mph top speed that it currently has. I know I can do that with a larger counter sprocket and a smaller driven sprocket. I have a custom-made larger counter sprocket installed on one machine. Before I get another for the other machine and also go the route of the smaller rear sprockets, I'd like to talk to anyone who has changed out or modified the springs in the drive pulley of the CVT. I've heard this can be done and want to know if that modification negates the need to change sprockets.

Ideally I'd like to modify my ATV to reach highway speeds of over 65mph. Before anyone tells me how unsafe this is, I've already modified the steering to accommodate this speed. I also know that this size of ATV is not designed for this, but just know that I am heavily modifying the rest of this ATV too for that not to be an issue.

Thanks.