As Fontyyy notes, (in my humble opinion) it's more likely to be a fuelling than an oiling issue I'd think. The condition of the piston would probably reveal all you need to know though. Was there any detonation damage on the piston crown and/or any alloy flecks on the plug? If so, he will clearly need to go a bit richer on the main on that side when he rebuilds it - and maybe check head volumes and ignition timing are safe if it's a tuned motor. Only if the plug is a good colour and there's no sign of the piston being nibbled by detonation would I (personally) be thinking about oiling probs. Obviously it's a good idea to run good oil -especially on the track, but in my experience oil starvation will often take out a bearing before the piston will seize in plated bores. I've never experienced that kind of seizure (oil starvation) on a motor that has plated cyls in fact. And I've known quite a few seizures over the years

Even when the oil tank of my TZR 3XV (pretty similar motor to an NSR) ran completely dry (dont ask ) and took out a big end, the pistons showed no sign of nipping up at all, surprisingly.

Good luck with it in any case.

Wb