I'd bring it inside as well....even though the internal parts of the motor are varnished to prevent corrosion....i have seen quite a few that have weathered the elements come back rusting.....still working but rust none the less.
If you cant get it inside and it HAS to stay outside, then the very least i would do is give it a few drops of 3-in-1 oil....spray the outside down with a WD40 like lubricant to displace moisture...and put a bag over it and stuff a few newpapers inside the bag to absorb any humidity and seal it up....it should survive just fine that way till next spring
