I know it's not a Screaming Eagle but I had the speed sensor go out on my 2003 Deuce. The bike lost the speedo and just would not idle at all. Once you backed off the throttle, even at speed, the bike would die.
After speaking with the local HD service guys they receommened that I change the speed sensor AND check to see if there was any water in the transmission. They said that any amount of water will kill the sensor. Sure enough, I had a very small amount of water in the tranny. Not very much at all!
Drained, flushed and refilled the tranny, installed speed sensor and the problem was gone for good. I'm guessing I did not tighten the cap enough during the last tranny draining.
Because the problem seemed like an electrical issue I was very surprised that a simple speed sensor was the cause.
Good Luck!