04 450r locked up

[8greecra]

tonight i was riding my 450r going down a hill in my back yard and all of a sudden the tires just locked up and i skidded to a stop . i can start it in first but as soon as i start to release the clutch i moves three inches and will not go ne further. i just got a new chain a sprocket put on with only about two hours of riding put on it and the chain isn't loose. i have no idea where to start looking first.
PLEASE HELP!!!!!!!!

[ThumPIN_450R]

Dump you're tranny oil and see how much metal is in it. I had this happen once and I exploded the tranny. The engine will start with the clutch pulled it but when you let it go a piece of a busted gear could be holding everything up and that is why it's not moving. I hope it's not what you got going on becuase it's expensive but it is a possibility.