I had exactly the same problem with my XVS dragstar 250. I traced the problem to the clutch cut out switch on the side stand, which was sticking. It dam nearly drained my battery! I literally soaked it in WD40 and worked the side stand with the bike on a lift. After a bit of brushing and cleaning the problem completely went away, and my bike is running 100% again.
Apparently, according to Raceways Yamaha in Fleetwood, this is a very common problem with the 250’s, and it can also occur with dirt in the carb or the carb float gumming up.
Hope that helps, if you haven’t already fixed the problem.
