You have something draining power that should be switched off, or a short to ground in the wiring. If you disconnect the battery it will probably still be charged in the morning.
Someone would need to pull fuses and disconnect components to find the power drain while watching the battery with a meter.
The battery and or alternator maybe defective, even new parts can be defective, look into getting the alternator and battery checked, if they are good, than you have some other electrical problem, maybe parasitic draw.
If your planing to rebuild the carb take the number off the carb to the parts store and order the carb kit. It will come with the information you need.