My Buddy has an 1989 Rm 250. After riding in deep water, he lost spark the next day. We found some water behind the stator cover. We believe he may have shorted out the stator. he is having difficulty removing the flywheel. Is there a certain type of puller that he needs to remove the flywheel? Also, how do we time the bike after we have it apart? And what else should he check electrically?