Hello;
I have a 1985 XT600N (North American Version) with Idling Issues.
Things I have done so far...
Pulled the carbs, cleaned out Most of the Carb But not all of it. I removed and cleaned all the Jets, Replaced the Rubber Coasting Enricher Diaphragm
(I originally thought this was a accelerator pump), removed the float cover and cleaned all that area - the float seemed to be moving up and down normally so just replaced the float back in its place after cleaning all that area out.
(At the time I had the Carbs Apart I was not able to figure out where the: Needle Valve & Valve Seat were located, was planning to replace them with New ones I received in a Rebuild Kit)
Did NOT replace the Needle Valve
Did NOT replace the Valve Seat
Did NOT remove & inspect the Jet NEEDLE - was sliding up and down smoothly though
Replaced ALL the Fuel Lines.
Reinstalled the Carburetors Properly.

ISSUE:
Kick Starts with the choke ON, let engine Idle at 2000rpm for about 30 seconds then slowly put the choke back to OFF position - Idle did not really change at all after turning choke OFF... blipped the throttle a couple times and the rpm's went to 5000rpm's and stayed there, after about 20 seconds I blipped the throttle twice, rpms's stayed at 5000rpm, blipped the throttle two more times and the Idle Stayed at 5000rpms, then shortly thereafter I shut the engine Off.
When throttle is Blipped the Carburetor Throttle returning back to Idle Position as it is Supposed to, Throttle Cables are NOT Sticking.
Air/Fuel Mixture Screw is set @ 21/2 turns OUT from Bottomed Out (turned all the way In)

I could not find any Past Troubleshooting info on this site regarding my particular Idling Issue.

"I would really Appreciate any ideas of what my Idling Issue could be".
Thank You