I have not experienced it, as my bike didn't required any engine part from last three year.. but my mechanic say he worked on Engine of a ravi previously, head/piston/rokkers/valve/tappets are different and easily available so no worries rest of the engine like clutch box, friction/presure plates are same other engine parts usually don't wear and tear so from engine side it is "SAKOON MAHOOL"
what worries me is its cosmetic parts like meter, silencer, fenders, seat tanky tappay ... I have not seen a single piece of them availble uptill yet, I hope they come in market as well..