AS a note to everyone: This plane has not moved yet. The owner passed away and the ownership of the plane is going through probate litigation now. Once that is settled the son of the owner plans to sell the plane. I have not been able to get into it's hangar for any details, but as soon as I am able I will find out as much as I can and post it here.
They were using the name "Hog Air". Harley-Davidson owns a patent on the term "Hog" in relation to their products. Not to mention they did not endorse or sanction the use of their products to power aircraft. For the true experimenter, this would be a fun, NOVELTY, engine. To buy this engine, designed fabricate a mount, design and fabricate a cowl and cooling system, trail and error on several propellers (at least), plus the multitude of other things, you could buy and be flying a Rotax twice over. It all depends what you want to do.
I have a Bose. It is the best money I have spent since I started flying. The bluetooth is nice to connect to my phone for music and calling. The ANR feature is without compare to a passive headset. Prior to this, I had an older Lightspeed that was large, bulky, ugly and literally it's plastic construction fell apart. When it did work, my passive David Clark was better at noise reduction. No comparison of this unit to the quality of the Bose. Newer Llightspeed units may be better, but I'll never know.
Again, an engine designed to loaf along at 1500 rpm putting out 10% of its rated power is going to be pushed to 80% continuous output. That sounds like a good combination for an airplane. Also, it's single ignition. I know for a fact that a HD will not run on one.
Have fun with it. I'm sure with the shorty drag pipes you'll make a lot of friends.