Contrary to common belief, many (not all) of the open frame motors in older brass motors are of exceptional quality. Depending on the size and weight of a model, you can install DDC decoders in some models without replacing the original open frame motor. Some older open frame motors can be cleaned and tuned which may eliminate the need for a new motor.

People have asked me “How do you tune just the motor?” Some motors, especially older motors, have lots of little adjustments that can be made to them. Frames can be reshaped to permit the motor to turn more freely. The layer of dirt and ground up dust from the brushes can be removed from the slots on the commutator which reduces operating temperatures. The tension on the brushes can be increased to provide better contact or decreased to reduce drag. And finally the old dried lube can be replaced with clean fresh lubrication. It all adds up, and sometimes the tuning procedure can free up a motor enough that a new motor is not necessary.