Just bought my YZ yesterday and it leaks a bit of oil right above the countershaft sprocket where the clutch cable pulls the lever. He said there is a seal that is under that little lever piece that needs replacing and that is why it leaks. I inspected everything really good and made sure it isnt a crack in the case or anything. It only drips oil when you ride it and just a little after you are done, but its not alot. Is there really a seal that goes there and how could I fix it?