Rotary Powered Dixie Chopper Lawnmower

no way in hell thats a rotary, it doesn't even sound like one

Having seen it with my own eyes, I assure you that it is a single rotor made of 13B parts. It's put together by Atkins.

looks to me like it runs on propane

Yes. That's what it says in the video description.

Single rotor 13b? Hmmmmm...

It's half a 13B with a custom shaft. So a 7.5B?

you mean a 6.5 B :)

how do you convert one over to propaine?

*Propane

That is a much debated topic, what I have found best is to seal off all parts of the carp that may leak (Needles, Float, etc) and use a device called a "Demand regulator" which senses the vacuum pressure of the engine and supplies the correct ammount of fuel. To get the fuel out of the tank you can use a un-restricted valve or an old non-opd valve if you can find one (try canada ebay)

Hank Hill would be teary eye'd right about now.

"It's... beautiful..."