Chasing gremlins and need some help

[tomtampa]

Stock 2002 GS 500, stock exhaust, jets and air box, still has brass caps on pilot-adjust screws.
Location- Tampa, FL
Symptoms:
Running rich, plugs are black and generally wet if it doesn't start straight away. Seems to be running very rich to begin with. Once started the bike will idle fine over 1500-1700 rpm. Also stalled out on me in 2nd @ about 4500rpm, when I went for a squirt up the road. Definitely flooding it at start up (no choke, no throttle).
Checklist:
Compression, etc (all good)
Vacuum, Intake boots, fuel petcock vacuum. (all good)
Fuel Filter Cleaned
Carb-

• Gaskets, O-rings (all replaced)
• Jets & passages clear
• Float Level checked
• Cables (throttle, choke) free and clear
• balanced carbs
• vacuum piston, diaphragm, (little o-ring)

Air filter
From what I have read and know myself to check, I have checked and changed if required.
The only thing I haven't done is rebuild the starter and checked the timing. (obviously the starter will not affect the rich mixture.)and timing does not seem to be off to me.
I don't want to really mess with the factory settings of the carb since I doubt suzuki got it THAT wrong.
Does anyone have any suggestions?? I have worked on all sorts of engines and can't seem to find the answer to this problem.
Hence I am chasing a gremlin!

[ohgood]

check your drain hose from the carbs. if you get mud dobbers in there, it will cause problems. also check your tank vent line.

your float height may have changed, it's an easy thing to check. i don't have a link right now, sorry.

bad gas - run a couple gallons of GOOD gas through your carbs (open the float bowl drains) into a jug.

there is a dude in tampa that actually likes to play with older (carbed) bikes. bobthebiker is his handle. might want to bring him a case of beer or whatever he likes. nice dood.

i'm in b'ham, or i'd take a look at it (used to live in tampa)

whatever you do, avoid RON's CYCLE SHOP (just off SR-60) like the plague. he left my rear brake caliper flapping in the wind and then cussed me out when i called him about it. real jerk.

Pure Acceleration is a great place to get help. Small shop, great folks, great advice. Watch out for Sideshow's ass tattoo.

oh, and ...... you can always send your carbs to the buddha and he'll work em over if you don't want to mess with them. it'll run fine afterwards.

[bigfatcat]

Seems like i remember the carbs are finicky getting them back together just right, how the float hinges thingies are secured have to be just right or you'll have stuck open floats which if i'm not mistaken means rich running.

[tomtampa]

Well I checked the float today, in fact everything I listed I checked or did today.
Just checked the timing, ignition circuits and valves again. All good. Checked for the sticky float as well. Seems like everything I check is within the tolerances. I went over the carb with a fine tooth comb and made sure everything was right. Still no clue.
I think the only option left is to rejet the idle to run leaner. Which theoretically shouldn't be the case. but really is my only option at the moment. Once it is running above 2500 it sounds and runs fine. Can someone tell me if it is necessary to change the mid jet as well or just the idle. Guess the only real way to tell is to check the plugs after a few miles.