High idle does not drop (2005)
I'm having an issue with the idle speed on my 05 track bike that I'm hoping someone can help me with.
On a cold start (e.g. after sitting overnight), the idle will start at around 2000 RPM which is normal for a cold start (my 06 does it too) but what isn't normal is that it does not drop down to 1200 after reaching ~35-40°C. It actually rises gradually. By the time it hits 55°C, the idle is around 2100-2200 and the fan is on!
Once the thermostat opens (the right hand side coolant pipes get hot around 80°C) the idle will start to gradually drop. Once the temperature reaches 100°C+, it drops to around 1400.
Curiously, if I leave the bike to sit for 20 minutes so the temp drops to around 75°C, when I start the bike it idles perfectly and will continue to do so until cold again.
While it's idling too fast, I cannot get the idle to drop with the adjustment screw. I can get it to go even higher though, so the adjustment screw is connected and working.
The first thing I suspected was the vacuum hose from the intake flapper that I removed, but it seems OK. When I try removing the plug it idles even higher, so I believe the plug is OK. All other vacuum tubes at the throttle bodies are connected and appear to be undamaged.
Given that it appears related to coolant temp, I suspect there may be an issue with IAC thermal valve.
Any ideas of what to check/try would be greatly appreciated.