I posted earlier today about my bike with a Fuelpak and how it started missing, backfiring and lurching. If this ever happens to anyone with a Fuelpak, this might work for you too.

Called tech support, very helpful and returned my call within an hour. Somehow, it came out of calibration. They don't know how or why, but I just recalibrated per the original settings and the bike is running great again. No backfire on decel, or at all, pickup is back and acceleration is smooth through all gears.