A friend of mine recently purchased a 2010 YZ450F. After about 10 hours on the bike the valve cover gasket started to leak where it seals around the spark plug hole. The oil finds it's way out of the weep hole in the head and makes a mess. When he took it apart some of the gasket had migrated past the valve cover and head area protruding into the plug hole. He felt that the factory had not taken enough care to make sure the gasket was positioned right causing the leak. After he replaced the gasket all was fine for about 12 hours and now the same thing has happened. He called Yamaha and they said they have not had any similar reports or complaints. Is anyone else here at ThumperTalk with a 2010 YZ450F experiencing this problem?