I specifically asked Dub Jett about ceramic bearings when I ordered my Bar Stock Jett 50 FIRE -

Maybe it's because at the RPM's these engines turn aren't gaining any benefits. On the other hand though, ceramics are used in turbines, but then again we're talking 120,000 + RPM's. I think maybe this is where the difference may come in.

Not an expert by any means, just my .02

George