Motorcycle Repair: 1995 XR600R Coughs and Dies at Idle, air screw, screw out

Question
I'm at my wits end here. I've got a 1995 XR600R that I can't get to idle without the "cough and die" happening. It's got a UNI filter with the airbox snorkle removed and a Supertrapp with 9 discs. I'm running at about 200ft to 500ft above sea level. I've adjusted the valves and had the carb off and all cleaned out.When I had the carb off and dissasembled I shot carb cleaner through all the orfices, blew compressed air through them and ran a single wire from a wire brush in them also. I've had three different pilot jets in it (65,68,70) and adjusted the air screw out in 1/2 turn increments (starting at 1/2 turn out) all the way to 3 turns out with all three jets. It doesn't seem to make a lot of difference if I run it at 1/2 choke either.I checked for air leaks around all the carb boots and intake manifold with it running and a can of starting fluid with a little straw on the nozzle. I couldn't get any change in the motor at all.When I turn the air mixture in or out it doesn't seem to have a real profound effect on the way it runs.At anything above an idle it runs fine (160 main, nice light brown plug color). The compression has been checked and it's at 155lbs. I finally got frustrated and took it to a local "Mom and Pop" bike shop. They are not having any luck on it either. They seem to think the problem is worse when it's warm. They're also convinced that it is an electrical problem becuase it runs too good the rest of the time. It will idle great for anywhere from 20 secs to 1 min and then just cough back through the carb and die. They are suggesting the CDI box or the pickup coils could have an intermitent short or open. But wouldn't these problems effect how it runs at higher rpm's? It also usually starts right back up after one of the stalls.When it's cold and you start it you don't need to use the choke and the choke lever setting doesn't have any effect on idle speed. Everything that I've read online to this point has said the pilot circuit is the cause but I've had the carb off three times and I can't find anything.Any suggestions that you have would be greatly appreciated and thanks in advance. My e-mail address is kdtghickman@comcast.net, thanks again Mark.

Answer
Hi Dale,

Well written description, Thank-you!

I have a question for you: What is the average temperature of your riding environment? I'll do the math and figure corrected jetting.

I'll send numerous tech files to your email address. Reply to my email addy for best results.

Respectfully,
Mark Shively