Is there any reliability data for Rotax engines, comparing them with the old Lyco engines for example?
Anecdotal evidence suggests Rotax are far less reliable than the old Lycos. They do however occupy what is for most part a different part of the market. A failure of say an IO-540 is going to bring down a 4- or 6-seat plane of reasonable size, and it will certainly get noticed. A failure of the average Rotax will quite likely bring down something which can land and take off from just about anywhere, so the engine failure may go unreported.