I picked up a 1/4hp stock feeder not too long ago and tuning it up I never got around to changing the oil. I ran only about 100 linear feet through it the other day for door stock and the motor got pretty hot. I checked the oil and I can see it is almost bone dry, which I am sure isn't helping at all. Does anyone have any brand particular oil to use for these that is reliable? The manual says to just use #80-#90W automotive gear oil. Thanks!