Topic: mystery hole in head

[Tim]

OK, it's all back together now without too many left over parts, and it runs good, but there must be at least one part I left out.  There is about a 1/4 in. dia hole in the head (CB500F), between the two inlet ports for the two middle carbs.  It does not appear to be threaded.  It opens into the timing chain space, I believe.  Should it be plugged?  Vented to somewhere?  Oil spits out this hole when the engine is running.

Thanks

[Einyodeler]

That is the hole for the bolt that secures the top of your camchain tensioner. ( see pic )

[Tim.]

If there's nothing in that hole, you might not have a tensioner in place 

Anything that looks like a green banana laying around?