Yes, your local Yamaha dealer will be able to get it. More than likely they will have to order it so be prepaired to wait a couple of days. For now I would take the cover off clean the gasket surface with carb or brake cleaner. Next put a little black Permatex liquid gasket on the entire gasket surface and put your valve cover back on. Only snug up the screws then wait an hour before you fully tighten the screws. You should be able to seal it up with no leakage that way.
