I'd echo Bryan and Mathewmosse, in that if they've been blocked on those really small low speed jets, it can take quite a while before you can get them back up to scratch.
Initially, as soon as you get them visibly clean and running, then they accumilate more problems.
You can get some idea of which carb is problematic by warming the engine and one at a time screw the adjustment in and out. If it's blocked you get no response from that cylinder. so at least you can pinpoint where you need to work.
Also, with them dismantled, you can use one of those domestic steam cleaners with a nozzle for ovens etc to clean the tubes within the carb bodies. It's used in chemical analytical labs to clean all the glassware, removes tarring, crystalline deposits etc and may help you get them fully operational.