The Fuel injection systems generally offer improved efficiency and reliability compared to carburetors, and they require less frequent maintenance. Therefore, if you have a newer model of the Enfield Classic 350, it may not have a carburetor at all.
For accurate and up-to-date information regarding the specific model year of your Enfield Classic 350, it's best to consult the owner's manual or contact an authorized Royal Enfield service center. They will be able to provide you with the most relevant information regarding the lifespan and maintenance of the carburetor or fuel injection system on your motorcycle.