NateHanson said:I've seen rebuilt or removed-running small diesels sold in my area on craigslist for under $2000, and frankly, you'll pay nearly that much for an outboard. An outboard hung on the transom will be vulnerable to swamping, damage from docking, etc, and won't work well if there's any chop, because way out back there, it will constantly be cavitating as the stern pitches up and down.
I'd definitely spend your $2000 on rebuilding the A4, or repowering with a little old diesel.