For the first 15 minutes or so it runs fine, but then it kinda defaults to a 2000 rpm idle. Sometimes I can control it by slipping he clutch at a light and half stalling it down to 1k, but after a half hour or so on the bike even that won't work. Strange that it does it ONLY after a good long warm-up.
Something is letting extra air into the intake when it gets warm.
Have you ever replaced the O-rings between the intakes and the head?
Did this get resolved?Mine is doing the same thing, except it wants to sit at 3/4000 rpm + when warm. The bike has not been used for a few years (lockdowns and travel restrictions), and so some sort of crud in the system is more than possible. However, after additives etc in the fuel, it is running fine. It got me to the south of France, and now I have the time to give it some TLC. Could it be as simple as an air leak, he asked hopefully? If so where to look first? Very grateful for suggestions.