missing vacuum plugs....

[T Cro ®]

That just sounds silly. I do not know what model that would be but I can tell you that will not work. Carbs have to be synch separately in relation to each other . If you join them together  then what  you did is not called 'synchronizing carbs'.

Mike before you claim BS you might try reading all the post and better yet try using Google with key words of carb manometer there you will find the device that is being spoken of. While not used by many when built properly they are very accurate; I had to be reminded of what they were to recall that my brother built one that stood like 4 foot tall and with that thing he could balance his BMW twins with absolute precision.

[tvpierce]

I got a pack of silicone plugs from McMaster Carr.  They should be good beyond the life of the bike.

[nevadazx12]

Just as an FYI, I have been running equalizing tubes between carbs on in lines fours for a few decades, started with my Z1 and I carried the practise over to the Connie.  I pair cylinders 1-4 and then 2-3 together.  No vacuum petcocks, both are manual or converted to one.