Thought I'd give an update in case anyone else is having the same issue. When searching for a new IAC valve, I found out that the '06 Black Scorpion doesn't have one. Instead, it has an Idle Air Valve, which is part #33 on this schematic
. It is located on the opposite side of the engine from the Flame Arrestor, just under the top cover. Once the cover is off, the part is very easy to swap out. In my case, the new part totally resolved my problem.