Thereís no need to be worried about messing up your timing by adjusting the roller chain and the steel detachable chain that are underneath the front of the plunger they only provide power to the pickup. On that baler the knotter and needle timing is all gear driven. I recommend you get a blue ribbon service book for the baler as itíll help you a lot when you need to service the knotters. I have a IH 430 and itís replacement badged as a new idea 555. Theyíre excellent balers once you learn how to keep the knotters happy.