The Carter is a good carb, else it wouldn't have been OEM from Detroit for more than 40 years.
Like any other carb, they need regular servicing. There are more than 15 settings and adjustments that must be right on these carbs for them to function to specs. Get it right, and it will be trouble free. Get it wrong and the engine won't run or will run poorly.
Even a quality rebuilt carb needs to have all the settings checked. Rebuilding carbs is fast becoming a lost art, but it is still being done.
I try to buy every BBD I can find from owners that think they are junk, I have never bought one that had already had the (factory recommended) idle tube mod done. That tells me something about how quick some are to blame the "crappy Carter" for their problems.
Rust free YJ for sale. Need more room in barn.