Having done about 6,000 km on the new roller motor I stuffed into my old bus I thought I'd check the valves.
While I don't know exactly how many km it had done as the dash was smashed on the wreck it wasn't many as the bike was in n it's original tyre's and they were barely worn. I'd checked them when I installed the engine but after 6,000 they had all tightened up a bit.
As I've noted before the roller motors open their gaps up as the engine heats up so you are unlikely to get any damage unless they are grossly tight. On mine, cold, they had closed up by about two thou all round and were at two thou inlet and four thou exhaust. I opened them up again to 4 & 6 and the engine was slightly quieter when I started it. Haven't ridden it yet but I don't expect any major surprises.