The fact that the idle increases by 450RPM after warm-up sure suggests a vacuum leak somewhere. My bike will idle at about 900-950RPM cold and warms up to 1000RPM hot, a change of only 50-100RPM.
After doing a big service recently including a TB sync, I noticed that the previous 1000RPM idle had crept up just slightly, no doubt due to all of the new-found efficiency! I took the side panel off my 2V RS to adjust the idle screw and found that it was not touching the stop. I loosened up the choke and throttle cables and TPS and still could not get the idle screw to touch the stop. That's not good, because it means the butterflies are providing the stop, and that will cause wear inside the throttle bodies and to the edges of the butterflies.
What I determined is that whoever set the TB air bypass screws last time had opened them up to about 2 turns each. I turned each screw in 1 turn and re-synchronized. Now I can turn the idle adjustment screw in so it will sit on the stop as it's supposed to, and still provide the proper idle RPM. Essentially, I had an "air leak" which was bypassing too much air around the butterflies and making the idle stop screw run out of range.
