Stuff I tried:

Put in some Marvel Mystery Oil directly into the spark plug hole, let it sit for a bit. I pulled off the starter, worked the shaft for a bit and got it to crank again, but it wouldn't start

Replaced the spark plug, didn't start. Verified the new spark plug works when it both shocked my hand and getting a spark plug tester. Put in completely new fuel

Next I cleaned out the carb, didn't run. Got a cheap replacement off amazon, still didn't run. Made sure that gas was going into the carb ( it was, there is fuel in the bowl)

Next I opened up the engine case, nothing looked out of place? I took out the piston, but that looked ok as well? I cleaned out everything as best I could, put it back together (made sure the cam shaft was lined up in the proper spot as well), and still wouldn't run.

It's not even turning over, or starting for a few seconds before dying. Anyone more knowledgeable than me able to tell me what I'm missing? The only thing I can think of is something is up with the piston and it's not getting enough compression.

Here's some pics of the piston, bonus if anyone knows where this lone bolt in the last pic goes

https://imgur.com/a/rdBpv2h