they have a purpose in tuning a two stroke. go too crazy with the reeds or the intake porting, and your idle will go to shit real quick, the 'boost bottle' picks up the low end and midrange throttle response, wont help you 'go faster.' its a pretty complicated and debated subject tuning wise, so i would say you are wasting your time unless you have a crazy ass bike designed to need one in order to run right.