Post of Shame - Chain came off and broke the engine casing

[marhaba]

Here is a post of shame that I hope I can get some feedback on (and maybe be an inspiration to others to check their chain tension regularly). I believe I let my chain get too loose and it fell off when I was taking a low speed turn. I immediately stopped and there was no crash. I just had to push it a few blocks home.

I've ordered a new chain and sprocket set and will replace soon.

My question is can I just leave the approximately 1"x3" hole in the engine casing? The only thing bad I can think of is that water may get in there when I wash the bike or when I ride in the rain (which is never). There is one bolt out of the 6 that will not be able to be used because the bolt hole was broken off. I've included some photos.

If I wanted to replace the engine casing, I assume it would be a long drawn out project where I would have to remove the engine from the frame and all.

Thank you in advance for any comments, jokes, advice. P.S. This is my first bike and I don't have much experience, but average mechanical ability.

The engine casing is broken above the front sprocket.



The place where the top bolt attaches is broken off. This is the top right bolt that goes through the metal removable sleeve before screwing into the engine casing.