So I traded my backpack blower for an old Toro Wheel Horse that I pretty much know nothing about. It's got an 8hp Briggs in it that seems to run mint. I have no idea how old this thing is or it's history, but I did an oil change on it and it seemed pretty think and black. I ran a quart of oil through it with the drain plug off and it took a while to make it's way out...so I think it needs a pretty good cleaning of some sort. Anyone have any advice on what to use, and possibly about how old a machine like this is? It's got a 5 speed manual and it seems like a chain drive.