
To rebuild the carbs properly you'll need new diaphragms or you will run into full throttle issues. I've rebuilt 2 and tried everything you see online
It isnt hard to get rid of the Airbox. I have 2 cb750's one is an 81 k four and the other is a 79 cb750f super sport. I run velocity stacks on both. All
I would just keep them for now. The other CB750s that have spoked wheels have a single disk brake upfront and a drum in back, so you have that to contend
Try this link:
https://bikebrewers.com/motogadget-m-unit-wiring/