fine tuning cold start/idle/low speed

KZ700, with apparently non-original carbs. Right model/size, but some details are different.
chasing little gremlins off the bike as I go.
I've always needed full choke to start, once started, drop to half until some arbitrary point that I move it in to no choke.

on full choke, it's stumbling HARD. with no throttle input, it will die promptly.
On half choke, it idles pretty low until its starting to warm up. Some throttle input helps. I don't want to adjust the idle screw up as that brings the normal warm engine idle up pretty high.

First question: what am i doing wrong when using the clear tube method to measure fuel height in the bowl? I let the carbs fill. attach clear tube to nipple on bottom of bowl. then open drain screw. More often than not, I end up with a large air bubble trapped between the nipple and the bend in the tube. And the height from measurement to measurement, on the same bowl, is different each time. I feel like i'm missing something simple.

second question: with no choke, if I pull "up" on the rack of carbs while it's running, the idle RPM climbs a lot. but pushing "down" does nothing. Am I altering the fuel level at some critical idle piece in the carbs when they're tipped up/forward? Or am I introducing a vacuum leak? I'd think if it was a vacuum leak, it would happen regardless of direction. The boots from carb to intake are new.

If there is air in the u-tube, level will not read right.   Can't recommend this, but what I do is blow gently in the tube, 2 or 3 times, forcing fuel back into bowl, and let it come out, until all air goes back into bowl.    Then moving tube up or down a little should always show same level....about the carb bowl top, if right. .

I personally don't understand what you are saying about pulling 'up' or pushing 'down' on the rack of carbs. 

.....and if it changes anything,...the "Choke' is probably not really air chokes, but enrichener plungers,...even the label says 'choke'.       .....Are all carb vacuum taps accounted for?

I will try removing the air in the tube that way.

the pressing up/down is meant literally. slightly pull the rack up towards the tank, or down towards the transmission.

i knew about the choke actually being an enricher? enrichener?  "more go juice knob"

Yes, all vacuum taps are accounted for. The reason I mention the carbs not being original, the diagram and parts list for the KZ700 carbs shows plugs used over the pilots. But mine can't use them. There is no port between the main jet orifice and the one for the pilot. If i put a plug there, the pilot would not function at all. I replaced the boots on the choke plunger shafts. I've confirmed the small rubber seals on the face of the choke plungers are still pliable and not damaged. It's using the stock airbox.

Is it reasonable to "read the plugs" from only at idle? Could I glean whether idle is rich or lean from there?

If moving rack up/down w/out moving throttle linkgage causes increase RPM, I'd say is causing vacuum leak in engine boots. 

 Am familiar with the Keihin CVK carbs used later, but I presume these are Mikunis.  Only plugs I can think of is the ones on the air screws,..probably epoxied to prevent owners from tinkering,...if these are factory.    If you don't think these are factory, I'd check all the jets are at least ball park.    Fuel level also determines mix. 

I'd say one would need some riding time to determine if plugs coloration is rich or lean.   Sorry if I can no be of much help. 

You indicate you think the carbs are not the stock ones for your year/model. You say there are some differences on the set you have and what is shown on parts lists. Not sure is this will help you with ID but here is some info related to pre 83 and post 83 versions of BS34 carbs that came stock on the 1000 and 1100 kaws. I know you have a 700 but if the carbs are not the stock ones maybe this can help you ID them. I am pretty sure all the BS34 carbs have an ID on them, but it may no longer be visible.

robscarbs.com/Kawasaki/1000-1100-AirCool...ooledFours-8105.html

It’s almost definitely an air leak when you lift the rack