Yes, I own the Wilson "Super" Monarch now. Chris changed the keel and the mast to Aurora parts so it could accommodate the 618 and a 68" prop. I got less than 25 hours on the 618 and it melted 3 pistons. I wasn't interested in a 3rd rebuild and more money to chase a gremlin. I bought a Red Gold Rotax 670 from Rotax Rick. Just finished the install and testing today. I had to install an electric fuel pump to supplement the Mikuni pump, as it was unable to supply enough fuel to keep the float bowls full at WOT. Works great now. Unfortunately, I don't have a basis for comparison between the two. The weather here is much hotter that the last time I flew the 618. But the 670 seems to be running fine and has plenty of power for me at 4600 feet and 90+ degrees. Leaving for Mentone with it tomorrow.
Goin' flying with the pros and all my friends!! :whoo: