I have two RV12 SLSAs in my school, and I am an A&P/IA, LSRM, and Rotax-Heavy qualified. I love these planes but want to publish some of my experiences to help you all out.
1. Definitely check for exhaust pipe cracks, even if yours isn't the one in the SB. I found my #2 exhaust completely broken in half yesterday. There had been a couple of flights that way. The #2 CHT was weird at first, acting opposite of what I would expect on a normal flight, then the EGT went sky high, but almost like it was a probe failing. The main issue was the exhaust that was staining the outside of the cowling where the hinge pin tab is. Also, it ran rough.
2. When it rains it pours. On the same day, while doing an annual, we found a crack on the bearing bracket that is in the SB. Sigh.
3. We have replaced both VRs with the Silent Hectic and love them. Don't leave the rotax original versions on your planes, they can cause damage to the circuit boards.
4. I opened up the gearboxes on both RV12s and shimmed them tight as possible. Made a huge difference.
5. Upload your engine data to savvyanalysis.com to analyze it. It is free.
Here is a link to mine: https://apps.savvyaviation.com/my-fl...4-6db2875dfa2f