I own a 2002 crf450r the other day i was ridding it and i went to stop to take a break for 20 min and when i went to start it back up the engine was seized, the kick starter wouldnt move at all. Then i had my friend try to start it and he free'd up the engine. I got it running and rode it for 2 min then it stalled and was really hard to kick. It wasnt normal. The top end was replaced about 2 months ago, so idk.