any issues running a counter rotating engine for a single engine use?

[spareparts]

i'd be more worried about what they came off of rather than it just being a counter, if it was the twin to a pair of offshore engines pushing a heavy offshore boat to the Georgetown Hole and back twice a week, something made them think to repower. Or if was a loose motor that ended up being rigged at a dealership( it happens more that you think) then its no big deal, just watch out for corrosion and check the play in the steering shaft, make sure your not gettings some one wore out motors off of their tournament boat.