Help: Valve Cover Plug

[sam98177]

Well, if it ain' one problem, it's another. There are a couple of rubber half moon plugs that's on the right side of the engine, between the valve cover and the heads.

I've had the valve cover off recently to clean and install new gaskets and had taken these plugs out, as well. Well, maybe I installed them backwards or not correctly, but when I started the bike, one of the plugs blew out followed by some oil.

Question: Do the plugs intall with indentation showing outward? I now notice there's a small lip that maybe holds it from blowing out if installed correctly. Also, do I need to put some sort of gasket sealer on them?

Which of the following should I install it?

[bikerphil]

The flat side faces outward. Those look pretty beat up, gonna have to use a good amount of RTV on the edges to get 'em to seal up. New ones are still available.