This is a high-quality processed carburettor with perfect idling and acceleration behavior. Easy to install and turns on instantly. Please make sure the fuel is pure enough before installation. You need to adjust the carburetor a little after installation because each scooter bag engine condition is different from ATV. Thanks. Fitment: This is an aftermarket carburetor replacement for all 47cc 49cc 2-Stroke Mini ATV Quads. This is an aftermarket part. aftermarket carburetor replacement with optimized combination and good packaging, easy to install instead of the original carburetor. Superior quality and greater durability Each carburetor is tested extensively and the idle speed and acceleration performance of the carburetor is guaranteed. The original carburetor is directly adjustable, easy to adjust, fill and ready to run in your locomotive deserves a powerful carburetor. There is no instructions on how to replace the carburetor, but you can search the internet, it's easy to find, thanks