Well,... if it ain't the petcock, or the needle and seat,... your floats have to be sinking...
That's all that left... you need floats...  test them by pulling them out and drop'em in a cup of gas... if they float, you're going to have to go over what you already did...
Gas can only come in two ways,... needle and seat, or down that vac line...

yeah, check the float level
if you have a drain nipple, connect a clear tube and run it up by the carb
open the valve and the gas should flow into it.
turn the petcock to prime and the gas should come up to the bowl gasket and stop.
if it don't, check the floats and the valve.

can't hurt to check the valve adjustment again.

It floods while running, everytime I come to a stop. It started doing it gradually, not all the time. Usually after warmed up. Then about 2 weeks ago it was doing it all the time every time, after warming up. When cold, seemed to run ok. Now, I don't even need to "choke" it when starting up.
The floats seem ok--not gas soaked or heavy.
Mixture screw froze in place at 1 3/4 turns out.

The result... runs the same as before...dies at idle, cruising ok.


Well,, you didnt mess anything up...just gotta find the problem.

Pull your float & shake it. If theres gas in it, youll know. If no gas in float, stick float in a pan O H2O & hold it down. Bubbles? Its bad..

Check a float for leaks, put in in freezer for an hour or so, then submerse in warm soapy water.

Excess cold air in the float will expand and exit as it warms up, making bubbles you can see as it exits the hole it entered by.   PULL THE PART OUT OF THE WATER JUST AS SOON AS THE BUBBLES SLOW DOWN -- it is getting ready to suck water inside as soon as the bubbles stop.

Mark the leak locations with a sharpie pen.

Float can be dried in a warm 100 degree oven (not hotter if float has plastic in it) or put over a heat vent for a week or so to get the water out of it.  

You have to get all the gasoline and or water out of it .....

You can get a float to puke out internal water by chilling it in the fridge then orienting the water "down" over the hole and warming the body pf the float with a hair drier (be gentle here, don't melt your plastic float !!!)   Expanding air will force the water out the hole -- repeat several times until all the water is out.

Use 2 part clear epoxy to seal the float up, then check it for leaks to find out if you got all of them.

A repaired float will require float height adjustment (the total weight has changed).

$80 with shipping, I'd at least try to fix it !!!    What do you have to lose, some time?

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Ours looks like a sheet brass float.   Solder joints are tough for non-soldering people to fix -- use the 2 part epoxy trick to reseal it.

You can heat your float up to 212 degrees F to get the water out of it, don't go much higher as you will melt the solder and the whole thing will come apart on you (ask me how I know this ...  )

Drums,... I know you rebuilt the petcock,... but try this test ...
It will cost nothing, and is quick and easy to do...

Test it by pulling the vacuum line off at the intake port, and blocking it and the intake port on the carb, ...(Note: just pulling the line will create a huge vacuum leak,.. both ends must be capped!)...
Then ride, with the petcock set to prime, and see if it runs better... If it runs better, the petcock is bad...
Don't forget to block these ends!