Hello Gino, the Zenith carbs are well documented and fairly easy to clean and rebuild. I highly recommend you get "Zenith Model A Carb Restoration Guidelines" by Steve Pargeter and/or "Restoring The Model A and B Carbs the Rex Reheis Way" by Gordon Biggar. Also be sure to use flow tested jets as described in these books. You can not trust used jets or jets just off of the shelf. Good luck, Ed