My 08 night train has a high idle sometimes. When you first start it up after its been sitting all night and cold, when you take it for a ride and get it to normal operating temp it will idle high. When it does this i will shut of the ignition and let it sit for a few seconds until the lights blink, then i start it back up and it idles fine and will idle fine for the rest of the day. But it doesn't do it all the time. It did it the other day when i went to work, let it sit all day in the parking lot, and it was fine when i went home. I also took a ride the other night and the bike was sitting for a few days and it idled fine that time. Any ideas what it could be?

 

Could be the IAC valve. This is the" idle air valve". Could be sticking. This is the little Top Hat siting on top of the TB. Has a little electric motor runs up or down, mostly depending on temp, to open a tiny valve to let air in and controls idle. Inlet hole is located at the TB inlet inside at the top.
Squirt some carb cleaner into this. Warch your eyes.