N.B. Do not follow the carb sync procedure in the Haynes manual. You don’t balance carb banks to each other. You balance the other carbs individually, in any order, to the base carb (#4). Adjust the rpm as necessary.
You might consider going through your original carb set and reinstall. A good cleaning and keeping the original jets and brass parts. Most of the time the only new parts you need are new float bowl gaskets. Buy OEM from Honda or get O-rings from here: https://v4dreams.com/products.html
Avoid splitting the carbs apart from the bank of 4 .....it's a real pain to get them back together. You can get to 2 of the air cut off valves without splitting the carbs from the bracket .... if those two look good don't touch the other that require splitting the set.
I've use these o-rings from V4dreams and they work and last. I have used the china float bowl gaskets and after a year or two they will leak.