Y our scooter is designed to operate reliably at the factory settings using factory components. In addition, the scooter is only EPA certified (i.e. legal to ride on the street) in stock form. If you make modifications and/or install performance parts such as big bore cylinder kits, free-flow exhausts, and clutch kits, this not only voids the warranty, but potentially makes your scooter illegal to ride on public highways. On top of that, when you install a performance part, it usually requires additional adjustments (such as changes in the carburetor jetting) that if done incorrectly can cause extensive damage to your engine.