If it was smooth before, then all that has happened is the bearings have gummed up, there cant be anything else wrong with them as the balls are ceramic and the cage/inner cone are stainless steel. The preload spring/spacer could also be sticky due to the dried up oil.

So long as you know your lube line is clear by adding some mixed fuel into the lube pipe with a syringe, if it empty's the syringe then it must be going through, this will flush the front bearing then the tunnel then rear bearing and help free them up.

The bearings will be getting lube when the turbine is run so having a bearing failure is not really an issue, bearings only tend to fail if they run dry. It would be different if the bearings had steel balls and cages and were rusty as what happens on glow engines that are lying for some time.

This all depends on how many hours were on the engine in the first place, if there are 20+ then maybe it should be sent off for a bearing change if not I would fire it up and let it idle for a bit then shut it down again and see what it is like.