Thoughts most welcome of the following.
My perhaps unscientific approach to carb balancing in the past was to use a stethoscope at the inlets, listen to the hiss, and basically to try and get the them all to sound the same. This seemed to work well on twin carbs fitted to old classic cars/bikes in the past in order to gain a reasonable balance, along with fiddling about a bit with the idle mix screws.
I still have the stethoscope, so would the same reasonable balance be obtained on the 4 carbs of the Honda using a similar method?
Alternatively, I have noted the cheap Chinese dial gauge stuff on EBay, and wodered whether they may offer a more suitable method...Clearly it may not be the best made stuff, but a more accurate method than the stethoscope perhaps?