Hit 30k on the odometer today .I've put 1700kms on the motor since I got my paws on it,doesn't miss a beat,tempting fate here, .Fuels brilliantly through the rev range.Compression is well within tolerences,am I wrong in thinking,if it ain't broke etc

The number one thing that kills NSR's is a detonation seizure, it's not prevented by maintainance.

But new piston rings and new pistons will (or should be) both be on the manufacturer service schedule on any stroker and this should be done. It's as important as any other bit of the service schedule and not a tough or expensive job compared to plenty of 4 stroke service items.
I've spun a ring (the little pin that holds the ring still drops out, the ring spins and an end goes into a port). Almost certainly caused by the pistons never being replaced.
Not to do it is a big a folly as not doing oil changes or not checking valve clearances on a hot 4 stroke.

At 30,000k's you're where Honda life the crank at. I don't know of anyone who'd change it though just as a precaution.
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Please do not PM me technical questions, if you can't find it on the Forum start a thread

Speaking from my very limited experience I'd say just run it!

If you think you'll be keeping it for a while a bit of a birthday could be nice and maybe make it safer to add some more POWER!!!!!

I do intend to refresh the top end,but I'm concentrating on getting my other MC21 back on the road.The bodywork has been sorted,I'm tempted to fit it on the running bike-it looks as good as new-but the weather is shocking and I don't want to ruin it