Not really. Doesn't really look like it belongs there.

 

No, there is no thread in the hole and there is one in the other side as well, looks original to me.

 

Maybe. The fiche seems to show something there. It's hard for us to tell, since looking at our heads involves removing fairing pieces. Maybe someone will see this who has their fairing already off.

 

Drain holes for the spark plug recess?

 

I've taken a look on my CBR and tried to photograph it. And it looks exactly the same in your photo with evidence of some oil seepage but I've never worried too much about it.
Hope that helps. I'll post the photo later .
Mikey

 

You might have some there but I don't know where the oil would come from.

 

It is in fact a drain, the oil is probably coming from the gasket/O ring where the top cover goes on the spark plug holes.

I just shone a torch into the hole and I can see the numbers stamped into the lower end of the spark plug.

 

Here are the photos as promised . If you need any thing else , let me know.
Cheers
Mikey

 

Thanks all for the help, now I need to stop the oil leaking into the the hole.
Cheers

 

Same system as my Honda Blackbird.

The gasket will have been dislodged during re-assembly of the cam cover.

Best way is to take the cam cover off again - seat the gasket properly with thick grease, then put cam cover back on.