Ok so I have an 08 Night Rod special will just over 1600 miles on it. In the last few months I have taken two trips out where I was doing in excess of 80mph and then afterwards as I got into a cruseing section of the trip I found that the bike wanted to surge a lot at regular RPMs. If I jumped on it she would respond and take off on command and at idol it was fine but again at regular cruseing RMPs was the surging. The first time I had it happen it operated just fine the next day when I got back on it. And no issues in town until again I went out of town and ramped her up good. Any clue as to what is doing? Thx in advance.
Basically your tune is a hair lean in the 3500-4500 range to begin with or it's too rich at the higher rpms and the effects of Adaptive from higher rpm exposure pulling fuel, these trims transfer back to lower cruise rpms, for a while. It will relearn that lower cruise rpm and the surging will likely stop.
Bottom line is the tune, factory or otherwise is not centered well enough to the point where Adaptive, (long term learn) will not effect surrounding areas. If trim adjustments are too much one area it can transfer over to another rpm area. The new learned trims cover blocks in the calibration, not exact areas so not real precise.
In a nut shell the ve tables are not populated correctly for the requested fuel or the requested fuel isn't the right amount after the Adaptive tries to dial it in based on the numbers.
Ron