Loosen that clay up and make your life a lot easier, Add sand peat moss and composted horse manure.
A couple inches of the sand and peat and about 4 inches of composted horse manure will loosen it up and be a dream to work. it will also give you better plants.
Yes, the predator engines are pretty good engines.
If you're fighting clay - put some loose gypsum on in, then till it in. That loosens our adobe up pretty well.
