i'm looking at this bike and it won't run. the owner says that the stator went out and he had that replaced and it ran for a while but quit on him on the trail and now nothing. is there any way to check the stator? the rotor/flywheel has some plastic looking buildup on it as well. any other things to check? the bike is in pretty decent shape and i'm pretty sure i can get it for $400. any other suggestions? think its a good buy?