As it turned out, I have THREE spare top end.
1, 92cc, cylinder marked 82cc, this is bored out 92cc w/piston in working order. It was originally on the bike at time of purchase.
2, Marked 85cc w/matching piston. Looks fairly new, no apparent damage.
3, Marked 85cc, This one I don't have matching piston. Looks fairly new, no apparent damage.
I do have an extra piston. This won't fit 85cc cylinder. I suspect it's 92cc piston.
I'll have Carlos(CN Racing) inspect them on Monday. I'll keep you, Mike or any RS mini road racer owner informed.