a few suggestions....separate carbs from rack first. Only disassemble one carb at a time. Take everything off that you can to strip the carb completely as possible. Don't soak ANY rubber parts or floats in carb cleaner. Soak all metal parts in a good brand of carb cleaner (there are many good brands suited for this very purpose.) Use spray carb cleaner in ALL passages and blow them out thoroughly with compressed air. Clean any removed jets the same way. The early 750 carbs are some of the easier corbs to rebuild, and have larger parts compared to the smaller bikes. As for a pre soak of the carbs before rebuild in soapy water, I'd choose a mild degreaser or solvent on the external surfaces instead, and blow off with compressed air as a start, because any water that gets into a carb is never a good thing. TAKE YOUR TIME. This is for fun and it's even more fun when it turns out right, so do your adjustments as per spec. to the letter. This is just my 2c worth, and I've left a lot out, but these are guidelines I've used with good results.
good luck!
