You probably should buy a Buelltooth module and get a copy of ECMDroid so you can do some data logging on the bike to see what is going on at that point. It could be fuel pump volume, or something like someone changed the tuning to have the rev limiter cut out at 3500. Without more detail its difficult to tell what is going on.
Before you ask "who would do that to a Buell?"
https://losangeles.craigslist.org/sf...264058144.html
Most 2003 parts should cross over, but not all. If you buy that parts bike, the only parts you will need are the ones that will be different. But, I am looking for the headlight castings for a Lightning, which may help make the decision to purchase it easier.