I think the most common lubrication points on the Japanese motors are oil points, tiny holes at each end of the motor; it reaches the bearings holding the motor axle. It's the same on some of the later Singer motors. The earlier type has grease points, they have somewhat larger opening fitting the tip of the grease tube. I don't think it should cause much noise however dry they are, but they run lighter when oiled.
It has been mentioned further up in the thread, but if you post a picture of the motor I'm sure someone will recognize which type you have. You can safely add one or two drops (literally) of oil regardless, but don't over do it. Some motors are supposed to be oiled and it's easy to over do it.
Last edited by Mickey2; 01-23-2018 at 03:45 PM.