Rotax 912 crankshafts are pretty much indestructible, some are 1500 hr TBO, but the last 5 to 10 years they have been 2000hr TBO. a 1500 hr tbo engine can be upgraded to 2000 hr with the completion of a few Service bulletins.
the tbo cost is substantial, as the crankshaft, and piston conrods are manufactured as a one piece assembly that cant be disassembled. they do not use copper slipper type bearings, but sealed for life roller bearings.
Unlike continentals, the cylinder heads can be easily separated from the barrels for overhaul of each component. i am lead to believe that the heads on continental engines are screwed onto the barrels to complete the "jug" assembly, and ove these are screwed together, cannot be separated. (could be wrong though)