How do Rexxer know the best tune for a certain bike and exhaust combo? Just wondering as not all exhausts are designed similar. Is it a general map they use to update your ECU?I'm sure this will work in most peoples case. As soon I get my exhaust I will be sending out my ecu to get a Rexxer tune. Having gone through a few bikes that were tuned properly. They all ran much better throughout the rev range, more power, and throttle response was much improved. If your running a stock bike I would say leave it that way. I have gotten used to twitchy throttle for now. Rode it in the dirt recently found it was much more noticeable again. Everyone has a different goal or outcome as far as what they want from their scrambler.