JHEnt
Guest
An individual rotor could become off balance if a rasp bar would be broken loose or if someone replaceing the rasp bars did not install them as matched sets. Basically it would cause a very noticable vibration especially at higher rotor rpm. The timing of the 2 rotors if not correct can cause similar vibration mainly when the crop is being fed into the machine. Incorrect timing will cause both rotors to be loaded at some times and 1 under load at other times. This will cause a large change in power required to run the combine and basically make it perform very badly. It my also cause engine surging. Most of the time this only occurs if one of the rotor drive gearboxes fail. Otherwise if after a repair to the gearboxes the conncting chains must be reinstalled so as to get proper rotor timing. If someone just throws a gearbox back on and does not check the timing then you would have this problem.