The Rotax is in my RV-12. I could bolt another one onto the biplane, but I really have no idea what engine that will get yet. There's something to be said for a radial on a wood biplane...
I've had one or two people tell me that the factory specified oil change interval is 50 hours. I had been changing mine at 50; I decided to go 100 hours this time around and have an oil analysis done when I change it. I haven't had the analysis done before, but plan to from now on. It's not too expensive and gives a way to watch trends over time.
I'm building an all-wood Celebrity. The steel tube fuselage was offered for a few years, I guess, but not recently. I'm really just getting started, working my way through a whole bunch of wing ribs. I do have a build log at http://www.botkin.org/biplane/
. I just wanted something for those warm summer days when all I want to do is go for a motorcycle ride, but we're getting rid of the bike due to all of the driverless vehicles. You know, the ones with someone occupying the left front seat as the car wanders more-or-less down the road while they text and update their Facebook status. Had to be a biplane, two seats, LSA, all wood, didn't want to weld. That narrows the field right down!
Basically, I spent 3 years building an RV-7, sold that project and bought the RV-12, and discovered (much to my surprise) that I miss building. Didn't much miss the cleco-drill-disassemble-debur-dimple-cleco-rivet cycle though.