A friend of my blew out the head cover gasket on his '02 426. He said he just cleaned up the bike, changed the oil and air cleaner and then when out for a ride. Not more than 10 minutes into the ride the gasket blew out on the left side. Has anyone heard of this before? I asked if the vent tube was clear and he said it was. Could that do it? He said the gasket didn't look hurt and could probably just reinstall in, but I would really want to know why this happened first. Any insight would be greatly appreciated. Thank you.