Depends on the KX, my R1 is rated for 2.7 0-60. I'm sure I can't run it that fast? I'm pretty good on a launch so it feels better and after all the work, my KX could actually pull it to close to 90. Then my R1 hooks up hits the powerband and is gone. It is going to depend on your gearing, engine, swingarm for the KX. I had to extend my swingarm just to keep the front end close to the ground to be able to launch.