I have the VH Fuel Pak on my '07. The settings are a bit rich as by the evidence left on the rear after longer rides. After my return trip home from Fl. I noticed a difference in not only sound, but feel of the bike. It runs rough as hell now and will shake your taint while sitting at idle. It almost seems as though the rear jug isn't in time with the front any longer. My question to you in the know is, would the Fuel Pak effect the timming of the bike over time? I have noticed more "pops" between shifts now that get a bit worse with the hotter the motor. I have 11K on the bike and to my knowledge nothing else has been done to the motor. I'm not sure about the settings of the unit, but there is a digital display on the pak that is set at "1" on the left and "0" on the right. My plan is to contact VH for a leaner setting, but I'm just not sure if this is more of a timming issue. Anyway, I feel whatever is going on needs to be addressed. This Glide isn't running like the day I brought him home and I am looking for advice. Thanks to all that reply!