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 the right side camchain tensioner. Three parts should fall out.
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?