I recently purchased an 04 WR450. It was fine on the test ride and on my local trail. However, recently if I shut it off in gear, the clutch will not disengage so it will start with the clutch in in 1st. Also, if I shut it off in neutral, when I restart later after it cools, the clutch will not disengage and allow it to click into 1st. It just dumps into first and kills the motor. At first I thought the clutch cable needed adjustment, but it is fine with the appropriate amount of play. Is it possible that the clutch plates are sticking? Any thoughts?