yeah, I think you just control the amount of fuel it lets through, but it does about the same thing a changing the jets, or so it claims. Like I said, check the site and see if it's for you, other forums on this site also talk about it so you can check them too.

 

http://cycleworksracing.net/phpBB2/viewtopic.php?t=622 The website im sure will talk it up just to sell it....but i dont know maybe the guy in the link is not mechanically inclined.