SOS R1100gs pulled out bolt on back of block, won't go back in

[Ryan0104x]

Went to do a speedy oil change and pulled out this bolt thi king it was the drain without hesitation

What is it? How does it go back in, it seems like it's hitting a spring or something of the sort

[Ryan0104x]

Found a post that this is the chain tensioner and put it back in the hole in the bottom. Seemed alright. Figured I should pull the wrong bolt out on the other side too for good balance...

It went right back in but the bike won't idle now. I assumed this was just to keep tension on a guide. I've searched up and down and can't find it on any diagram. Any insight would be helpful. Thanks

[Ryan0104x]

Pic attached

[Ryan0104x]

I'm parked on ground that isnt level so it's possibly I'm under filled , would that cause the bike to stumble and shut off when cold? If anyone can even tell me the name of the part between the (head&block?) That would give me somewhere to start.

[SteveD]

Pic attached

That's apart of the right side camchain tensioner. Three parts should fall out, the bolt, a spring then a reservoir bit.
The left side one is above the barrel, rear and adjacent to the block. Access is much harder and removing the throttle body helps. I have a 17mm modified by thinning the neck so that t'll turn just enough to move the upper/outer left cct bolt.

Can you do a wider picture showing where the bolt in the first picture is from?