not running right.

[hondarider110]

i have a 2005 450r that wasn't running right so here's my problem. i was practicing on it on my first practice session was a bout 8 laps, when i went out for my second session it wasn't running right, it would spit and sputter on the bottom end, i was thinking stator but when i was riding back to get off the track it completely died. and the motor was locked up but then freed up later. any help is needed.

[gt400ex]

Check to see if your making oil, by that I mean that you could have a bad head gasket and maybe hydro locked, then when the coolant drained down past the rings it would free up.