Have they learned to make HIGH precision bearings yet for their jet engines? I lost track after MiG-23, but the problem at that time, when Lt. Belenko defected to Japan with a 23, and left us examine it, was, as he told us: You can only operate the engine at full throttle for a specified number of seconds. Beyond that limit the bearings are shot and the engine needs rebuilt. So I’d guess they’re liars.
Yes, they have learned to make high precision bearings in their jet engines. They don’t quite last as long as ours but they’re in the same ballpark. It’s China that until recently hadn’t figured it out yet and had jet engines with 30 hour lifespans. (Not a typo.) However, a couple years ago they developed the Taishan jet turbine which has a 2200 hour MTBO.
For comparison, the current Russian ones have a 2200 to 4000 hour MTBO and the most common US combat aircraft turbine - the F101 - has a 4000-6000 hour MTBO depending on variant.
That said, the Russians have sometimes made better turbines than we have, at least in applications where the turbine isn’t providing direct thrust such as in helicopters.