After quite a bit of help from Loud I got it started up and running without the choke. After a lot of minor adjustments with the air adjustment screws and the idle speed adjuster I got it idling down to 1500, but the gauge was bouncing all over the place.
Turns out there is an air leak in one of the intake manifolds. I'm going to order a new set from Z1 and ideally that should make it easier to diagnose further.
Out of curiosity - what do these old KZ's typically idle at?
I'll give you an update after I get some parts in.
The idle should be set to 1000 to 1100. If it's cold out, but the bike has warmed up, set it to 1000. If it's hot out, 1100. (It will tend to climb a little as it warms.)
The best thing you can do to improve the running is get an electronic ignition pickup plate and rotor from a later 550.
Then get some coils from an 81 KZ550D1 gpz. They are still available from Kawasaki for about $150 pair.
And make an igniter for about $50. (Plans in my signature)
This will eliminate all the variables of the points ignition during tuning.
I realize it's all stuff for the future, but something to keep in mind.
#1 problem of all carbs is clogged pilot jets. that is why engine runs only on choke after a bike was stored w/o starting.
#2 problem, I think, is clogged holes near throttle edge
