Did you get the part number off the needle jet ?
It could be helpful.

My oh my, that is one gooey lookin mixer.  Thanks for the photos.  Now we know what we are dealing with.  My compliments on how clean you have managed to get it.  Tell us more about how you are cleaning, what brand of cleaner, etc.

Although this problem is not consistent with your complaint, it is still a problem and needs to be corrected.  Your enrichment jet is plugged.

And I suspect the well for the enricher jet (the well is located in the float bowl) is also probably fouled.  There is a tiny passage that connects the well to the bowl.  Well circled in red, passage circled in yellow.

The passage in question runs from the main air bleed at the carb opening to the hole where the needle jet resides.  This shows the main air bleed.  Make sure its not plugged up.

Our friends from the Southern Hemisphere have reported a problem that could cause exactly what you describe (engine signs off about 4500 to 5000 rpm).  Seems the Suzuki factory delivered their motorcycles with a plastic stop in the slide assembly.  That stop limits slide travel.  Why would anyone want to do that?

Although there are many passages running through the carburetor, very few are submerged in fuel when the bike is at rest.  If you have plugged up passages in the carburetor, they will most likely be below the fuel level.  So anything above the float bowl gasket stands a good chance of being clear, and anything below the float bowl gasket stands a good chance of being plugged up.

A number of folks have mentioned that you should be using OEM jets.  I agree.  Ditch the eBay stuff and use only OEM jets, needles, etc.  You just don't know what you are dealing with when you install that eBay stuff.  Jets are precision orifices.  There's more to them than just a hole.  The angle of entry/exit and sharpness of the interface control the flow through the orifice.  Put in the OEM stuff so you can rule out the aftermarket blues.  It's easy to find the genuine Mikuni main jet and pilot jet (no emulsion holes in the pilot jet).  The needle jet is a special stainless steel item.  It doesn't wear out and you should be able to clean it up.  If your needle jet looks like brass, it's bogus.  Get the genuine OEM Suzuki part. For 1988 thru 95, it's a 766M X-8, for the later models it's a 766M X-7.  Same for the slide needle.  The needle is special.  You won't find it at Jets-R-Us or Sudco.  Buy a genuine OEM Suzuki needle. For 1988 thru 95, it's a 5C16, for later models it's a 5C39. 

I personally like Babbitt's Suzuki Parts House, and my local Suzuki dealer is a pretty straight shooter too.

Good luck,

Mike

Reviewing situation
Idle to half throttle operation is normal.
Problem occurs at half throttle or greater:
Therefore I followed the main air and jet circuits.

Couldn’t not find any major conclusions. Though after looking at the Transient Enrichment Valve (air cut off diaphragm) notice small tears and rips on one side. I believe it may have been my fault when I first did a carb cleaning I didn’t disassemble that part of the carb before spraying carb cleaner which can cause rubber material to expand and stiffen. I have to repair or replace and update the thread with my findings.

In the mean time anyone else want to share their experiences with bad or damaged air cut off valve?

Update
Took the stock main jet and drilled out to 3/64” response was much better more smooth. Still has one rough spot.
I forgot to mention I am running a nufoam air filter.