My FXSTSSE2 has 1600km's on it. Had the dealer do a service recently, oils etc. I don't understand tuning magic but even so I said it didn't feel right. It had been farting a bit and slipping gears on change down and making some seriously clunky hits in the process. As part of service they updated Thundermax firmware and "tuned". The ThunderMax was put on I assume by the dealer soon after the bike was purchased by the original owner.
The video shows what I now have. Starting is most often a grumpy affair. Often when I blip between changing down it farts and is unhappy. Yesterday it actually stalled after starting and then blipping. Holy molly. Sounds like a grumpy old tractor. I think the grumpy blipping may be effecting the "smoothness" of change down between gears?? Feels like it.
I have some sage advice to reinstall original ECU and O2 sensors etc and re -tune.
Check the youtube video. Thoughts?
https://www.youtube.com/watch?v=X7emCti6bZU&feature=youtu.be