Thanks to the info put up by others I have done my overflow tubes and in the process came up with a couple of questions.

First off did I miss the memo on using two different lenghts of tubing for the two different float bowls? I did two and two and assumed the tube length from the first set was correct for the second set but the 41mm I used on the first set was too long for the second set by a couple of mm.

Second question or idea...at the same time I purchased the .125 brass tubing I also picked up some .093. The .093 fits inside the .125 and I was contemplating sleeving  a piece in with the thought to reduce evaporation of the fuel. I could also roll the top edge of the tubing to get an even smaller opening. When I put the .093 tube in it only goes as deep as the point where the larger tube contacts the float bowl. In other words the press fit has squeezed the .125 tube down.

Sounds like you might be over thinking or over complicating this over flow tube thing.
First off- your fine. Leave what you have as far as  the height thing.
Do not be concerned about evaporation. There is a simple fix for that. Add some rubber hoses s to the bottom nipples on the bowls and 'T' them together so you end up with one rubber  over flow hose and put a loop in it. Now if  you want put a couple of drops of oil in the loop.
Your finished.

First wife said I was clueless, second says I'm thoughtless and you say I'm over thinking....VBG

Well it looks like I'll get a chance to see if putting the smaller tube inside the bigger is any advantage....after a 30 hour leak test the first two passed but the second two that I had to press back out a bit then take a few mm off of have shown a small leakage. Looks like SISF knows what he's talking about.

Pulled out the original tubes and have pressed in dual tubes...if one is good two is better.....testing is in progress.

BTW I did the first two bowls then had to do a few other things one that resulted in me slicing my left index finger, not intentionally, and getting stitches. So then I got back to the bowls and then onto the solvent testing. Did you know that when you spill solvent onto a fresh wound you will not be over thinking anything...LOL

I don't like the idea of limiting the diameter of the tubes. they're meant to stop hydrolock, and if they don't flow enugh they may not function well enough to effectively vent off the excess fuel. As far as lengths, 1) don't infringe on the drain screw hole, and 2) make them about 8 mm above the bowl parting line. Do the drain hose dealio and you'll have  about as good a setup as can be done. HTH, steve

Steve thanks for the input, I did follow your advice about the 8mm over the parting line. Trouble occurred when I split the job up and wasn't paying attention to the difference in the bowls....did a little, if 2mm is a little, infringement and could only do a push back and a trim which equals leakage.

The two tube is a tighter press fit even compared to the newly drilled hole and press fit.

Picked this set of carbs up from SASmayhem who had sent another set in to you for your magic so I do have another set to work my voodoo on. On to setting the float height and putting in your 2 minute mod kit.

I knew there was a reason I was missing my previous fuel injected bike....