A few weeks ago I was riding my 1998 wr400 and the engine cut out on me. Back tired locked up so I pulled the clutch and rolled to the side of the rode. I tried to kick it over but the kick-started wouldnt move. Just last night I was looking at it, and it kicked through. Could it have seized up due to overheating? I had just changed the oil a few days before the incident. Could it be the radiator?