As far as choke setting, I don't know. I didn't know it was adjustable. It will run on fast idle until I hit the throttle to idle it down. Seems normal to me. Idle mixture screws are turned out evenly on the center carb. Don't know about the outboards. It has always done this since I've had the car, and I'm not too worried about it since it smoothes out nicely after it's warmed up. I was just curious if this was common. loco340cuda, I am also out of town on business and won't be home for a couple of weeks to mess with it.