pull the bolt from the center of the flywheel, then use a flywheel puller to pull the flywheel and check the woodruff key (Part #92038 in the generator diagram on bike bandit). If is in 2 pieces, order a new one and a new generator cover gasket and reassemble. If not, look at something else, such as the kips valve (check justkdx website for a good description and picture intensive breakdown of the process). The flywheel is also the timing for your spark and if the woodruff key shears then it allows the flywheel to move and throw off your timing. Not a bearing issue, simply a 3.00 part with a checkered history.