My 2005 was doing the same exact thing. Felt like it was spuddering when I was talking off, loss power, started dying on me as I rolled to stop lights, even got as bad as taking off from a stop in traffic it died in my inn ther middle of a intersectional couple times. I bought the bike with 4k miles on it in March and added a light kit on it in July. Before digging into it, I took the battery off and stuck it on a charger and it was at 50%. After a full charge, the problem has gone away completely. Just a little fyi if it helps you. Good luck bro.