Mc Culloch drone engines came in several versions, 24, 60, 72 HP and 90 HP. There are aftermarket things available to make a Super 90 as well. They are VERY LOUD, very difficult to muffle and seem to explode with no warning. They can be had for around $100 by following the experimental airplane and gyroplane forums. Not very useful for an airboat though. Did I mention they are 2-cycle as well and it has to be premix, no automatic oilers on them. Also single plug jugs as well.
Can you imagine what the prop would look like after a trip out in an airboat?
I would steer clear of them myself. That advert appears to me to be WAY overpriced.
Scotty :wink: