Hey ibyers
Being the current owner of some 10+ CB750 4's, I seem to have a ton of experience cleaning carbs.
Easy solution, and you get to eat stuff!!
First, go buy two 4 litre pails of the cheap ice cream, flavour of your choice!
Second, eat said ice cream!
Third, drill small holes in the bottom of one of the pails. The more holes, the faster it drains. Ensure holes are smaller than the parts you are cleaning. I use 1/16" drill bit.
Fourth, go to CT, Parts Source, NAPA or any place else and buy a container of GUNK Hydro Seal II, and at least one can of carb cleaner per carb, some rubber gloves (not the latex gloves, but good rubber gloves).
You now have a dipping container and the best carb cleaner out there. The two ice cream containers stack together perfectly!
Remember, WEAR the gloves, trust me. Wear eye protection too. The stuff is toxic and will eat through rubber FAST, but cleans better than anything. Also, it can be neutralized with water!
Remove ALL rubber gaskets, dissassemble the carbs (one at a time), let sit in the solution for a while, then shoot all passages with the canned carb cleaner, reassemble and you should be good to go. You'll have to make sure all your needles are set properly and that the carbs are balanced after too.
Save the GUNK stuff because it is still good. Can clean about a hundred carbs! Just don't get water in it. Run it through some cheese cloth when you put it back in the can.
Good luck and enjoy the ice cream!