Many excellent suggestions here, most of them I learned the hard way. I have the same machine and it was in pretty tough shape when I got it but picked through it mechanically to the point it was squared away and deserving of fresh paint. It is a great machine and i use it for plowing my parking lot, towing dead cars around and odd tasks. My motor runs good and i am checking the oil often to err on the side of caution to keep it that way. Having to rebuild it would be a concern.
