Athena Aprilia 50 40mm Bore 50cc Standard Bore Cylinder Kit w/Head

If you're rebuilding the top end of your Aprilia 50, this standard bore cylinder kit from Athena is a solid option to get your engine running like new again. It's designed to match the original performance and reliability, making it a straightforward replacement for worn-out components.

This kit features a lightweight aluminum cylinder with a nickel-silicon coating on the barrel. This coating helps reduce friction, which means the piston moves more smoothly and efficiently. The included piston is also designed with reduced friction in mind, contributing to the overall smoothness and longevity of the engine. You get everything you need in one box: the cylinder, a complete piston assembly with pin and rings, and all the necessary gaskets to seal it up right.

Because this is a standard bore kit, it's meant to replace your original cylinder without needing any machine work, as long as your original cylinder is still within spec. Just be aware that this kit is not CARB approved and cannot be shipped to California.