I'm with pipedr on this one. It is probably a "simple" lectrik or loss of air issue and hopefully not a seizer. If it seized up, it would have locked you right up and done a power slide.
Hope it is something simple.
Do not over diagnose it, things like this usually turn out to be the easiest thing to fail. The oil lamp will come on regardless whenever the motor shuts down, don't think the worst, think SIMPLE! Look for things like a lose battery wire, bad plug, bad CDI, pinched wires... if it turns over, the motor is most likely fine. If a valve gets sucked/bent it will make a lot of mechanical noise (ask me or Jaymo how we know this) and blow a ton of smoke out the pipes at the same time. Kinda hard to miss this sure tell sign of valve eatin.
