Khornet....you've got a private mail awaiting you!

gotcha Thanks Len!

I just went thru them all. I picked up a $.40 medical syringe at walmart that fits nicely in that brass tube and allowed me to inject carb cleaner down thru that tube/jet. I pulled all the "starter sets" and I saw the cleaner freely flowing thru each. I put it all back together, reinstalled the carbs and it appears I've now made some great progress. It's still not perfect but the bike mostly idles now without the choke and is much more responsive to the throttle.

I still haven't connected up the airbox yet, but this is very encouraging. I'm now trying to figure out how I'm going to get those airbox connectors in there. so I've got a "real world " test. I think a good long soak in some hot water is the start, so they will at least be more pliable to work in that cramp space.

Not sure how your clutch cable is routed, but on my 650 it is almost impossible to get the intake boot for #3 in from the right side because the clutch cable blocks access. Much easier to do it from the left.

I do them 3, 2, 1 from the left then #4 from the right.

shouldn't be an issue, the cable isn't even close.

Hook-up the two inside ones first.
Do the two outside ones last.

Make a tool that you can use to "Shoe Horn" the Boots over the Intake necks if they don't just fold-back and flop right into place.

Use the locating tab on the outside diameter of the Boot to line it up right to get them on the way they came off.

Make sure the tool you make doesn't have a sharp edge that will slice the Boot.

Already Done! took about 15 minutes of Mr Circus Rubber hands to get all those airbox boots installed.

Now it runs even a bit better but still revving high and not coming down immediately (but least it does eventually come down now). still idles at @1200rpm nicely which it never would do before.

I'll give it a fresh tank of new premium gas, some Seafoam, and then I'm going to ride it a bit to see if it gets better. If not I'll take yet ANOTHER look at those slides and break out the polish.

12-Hundred isn't Idle.
12-Hundred is just off-idle and you are probably bringing-in some Main Jet Fuel.
Try adjusting the Idle Adjustment Rod, below and between the 2 & 3 Carb to reduce RPM's to below 11-Hundred.
1,050 should be the High-side of Idle. 900 being really good and dependent on Pilot Mixture Air~Fuel alone.

If the Idle Adjustment Rod will not adjust-out the High revving Idle, you may have to undo the Throttle Cable Slack adjuster at the Throttle Perch to slack-0ff the Cable slightly. There should be a little slack in the Cable to allow the Throttle Butterfly's to close.

It sounds like you are close to being where the Bike needs to be. Bear in mind that the Final adjustments are determined by actually looking at individual Plugs after the Bike has been run some.

When you get ready to make >Tweak< adjustments ... the Tweaking is a VERY SLIGHT movement of the Pilot Mixture Screw.
Since the P-M-Screws are ultra fine threaded ... you may only need to Enrich or Lean-out an individual Screw with a slight movement.

This SLIGHT Movement is measured in degrees. Not anything in fractions.
You should inspect the Plug.
Determine if that Plug's color is too Dark or Light and make the adjustment accordingly.

When determining if the Mixture is too Lean, you have to take a close look at the Ceramic Tip surrounding the Plug's Base Electrode.
The Ceramic will be colored from the Combustion.
If the Plug is looking CLEAN ... a Lean condition is happening.

Too Lean will overheat that Ceramic and cause it to deteriorate.
The Ceramic will also begin to show hairline fractures from the stress of the hole being too Lean.

Too Rich is obvious. The Plug will be dark with unburned Fuel stain.

You should Tweak the Pilot Mixture Screw of that Cylinder until the Plug is Tanned or a light Brown.

Don't be persuaded by how well the Bike will run in a slightly LEAN configuration to leave it Lean.
Too lean is a HOT Mixture that will soon take its toll on the Engine; causing the gases to be too hot and subjecting the Valves, Seats, Piston Crown, Cylinder Hole and Cylinder Head to higher temperatures than Normal.

You look to achieve a coloration of the Plugs that is Light Brown.

Within this window of find tuning is a narrow window of differing performance.
Lean: Faster acceleration, crisp throttle and engine braking.

Rich: Smooth application of power, smooth acceleration and engine coasting when the throttles are closed.

WOO HOOOO!!!!! IT's ALIVE!!!!!!

Started her up today and let it run to operating tempeture. I noticed I now had good throttle response, although running at 4K rpm. Made me think the idle speed was just way out of whack so I cranked it down and it's now running great! Idling normally at 1K with no choke.

Time for fine tuning. I'll pickup one of those colortune plugs and a Carbtune for sycn'ing them all. Between the two bikes I'll get my money out of both. (I've already got my YICS tool). Probably need the valve adjustment tool while I'm at it.

I can't thank you guys here on this forum enough for your comments and giving me the confidence to jump in on this and resolving the issue!

Len I still owe you a call and you'll be hearing from me in the next few days.

Idle spec for the 550 is 1200rpm.

This is according to the Clymer's manual.

I've got her idling comfortably at 1K without any further tuning.