I got the mystery solved. I pulled out the plug and pushed the bike and there was a spot where it would kind of get stuck, like the piston was hitting the spark plug or the clutch gears were getting bound up. Also note that it was hard for me to start, and that spot where it gets stuck is why. Anyway, I pulled off the cylinder and I noticed that the piston had some divots in it like something was bouncing around inside, although it was only in 2 spots. I looked in the cylinder and saw these same marks on the flat area around the combustion chamber (don't know the term for it). This was actually from when the cylinder got damaged from before, and I knew about it and thought I fixed it by grinding down the messed up spots in the head with a dremel. Obviously I didn't do a good enough of a job and it still hit the piston. I cleaned up everything again and made sure the piston and combustion chamber were smooth there were no bumps. Problem solved. It didn't get stuck when pushing it, it's easy to start, doesn't detonate, and the compression reading came out at 180psi.