I assume you made your sync tool according to this thread ---
http://www.thegsresources.com/_forum/showthread.php?t=174436&highlight=manometer ---did you use glass bottles or plastic?--hard to tell from the video
---I also made this same device out of four vodka bottles--works very well on my 82 850L. What I did was get the fluid levels in all 4 bottles close to the same (doesnt really matter if they are even levels or not when you end up, as you are just using the bottles to see which cylinder is pulling more vacuum.
---When i first started the bike up the #3 cyl bottle was bubbling from the tube and the fluid level was rising very quickly (i.e. pulling greater vacuum) (since the first screw you adjust is the one between 2 and 3, as Steve and the book says, thats what i did) you are merely adjusting the relationship between 2 and 3, so as I turned the screw (i dont remember which direction) I came to a piont at which #2 started bubbling (pulling vacuum) and #3 stopped--then i found the point at which about 1/16 of a turn one way caused number 3 to bubble and then 1/16 of a turn the other way made #2 start bubbling --i figured this "mid point" means that #2 and #3 are synced and left that alone--doesnt matter where the levels are on this type of device.
------Now doing this made #1 and #4 go back and forth----then I adjusted the relationship between #1 and #2 finding the mid piont again---then went to #3 and #4----then i went back and forth a few times and blipped the throttle every so often to make sure nothing changed, then i locked down the nuts.
---Basically when all was said and done, all bottles had different levels, but they were not moving and #3 was bubbling very very slowly--if i tried to get this to go away it resulted in either #2 bubbling slow or #4 bubbling slow depending on which screw was played with.
-----in answer to some of your questions--the sync screws are just adjusting the butterfly valves on #1, #2 and #4 (i think) #3 adjustment is your idle screw/knob--once you get it synced just turn your idle to where you want it--this is moving all 4 butterflys at the same time in unison, you only have one idle screw/knob below the carbs between #2 and #3 carb.
get a box fan to cool the motor as you are doing this--but all of this prob didnt take about 10 to 15 minutes.
Also, I am adjusting at the screws with lock nuts on them, and I can't seem to find the idle screws for each carb, are they under the solid looking piece of metal that looks like a filled in hole on the top of the carb just on the other side of the mixture screws?
-----the screws with the locknuts that you are turning are sync screws that adjust the butterflys
---also, how come you used oil and not water,, water is heavier than oil and seems to me that would work better and be neater, and can prob see bubbles easier. As for your mixture screw question, the screw coming strait down from the top on the side of the carbs closer to the airbox is your "idle air mixture screw" turing out or counterclockwise gives a richer mixture--start with 2 1/2 turns out from lightly seated on the bottom, then use the best rpm method on basscliffs website to obtain proper mixture setting--this is a good time to do this while syncing carbs
----what I noticed after doing this was smoother throttle response, and some little misfires that i felt every so often pretty much went away--also seem to have more power at lower rpm--i can wait longer to shift. This is definately a worthwhile procedure if you want your bike to run like a scalded dog.
-----critics please respond at your leisure--this is how we all learn--and after cheking out a few other forums for my other bikes, this one is light years ahead in correct tech info and i hope i havent messed that up with my explanation of bubbling bottles:-s