I was in Jha's pit when their NSR nipped on about lap 2 of the Suzuka 4hr. They had the thing out there again in about 15 minutes by just sticking a new piston in there and throwing a barrel on. It completed the 4hr with no further trouble.
On the other hand I've seen an NSR spit the dummy in morning warmup, a new top end fitted and run in and then stop again after a couple of laps of the race with a broken big end.
Choice is yours. At the very least give the case a good wash out with some fuel and oil mix. Catch the juice in a clean tray to see if any bits come out. If there's anything nasty then it'll be worth pulling it apart.