700K is a good deal? Seriously, I thought it would be a lot more! I wonder what the cost to fly would be for 100hrs? BTW it has been cold, wet, and SUCKY weather. Winter boredom has set in. LOL! http://www.islandaero.com/airsales/cobra.htm
You'd have to mod the oil system. I think on some motors part of the down housing is the "oil pan". Plus it needs a gear drive. They turn 5-6k at wide open. I used to wrench on outboards in the early 80s and now on my own stuff. Thought about putting a V4 OMC on a plane, but gear drive, cooling system, etc. It would be a war horse though at 115 hp. I don't want to even think about my 280hp Merc!!!
And the single ring, I have a set of Wizard pistons (http://wizardraceshop.com/) in my Merc 225 ProMax... ???? I think it is a efficiency thing... How much blow by do you get? Unless it is worn two rings would be better?
I was thinking about coatings before I got to your post, if anyone flying was running coated pistons. I too run hotrod two strokes, but outboards. The last set I had done, he had a teflon coating for the skirts and a ceramic thermal barrier for the crown. He didn't do the ring lands though... I wanted them done too as an experiment for carbon build up.