Paz the taper looks like shit now that I looked at it better, so that could be an issue, and I'm still having this issue, but not the loosening. I don't have a torque wrench right now, but it seems like if I crank it on there fairly good, the clutch is always engaging and spinning with the bell. Don't I want the clutch to spin on it's own till I pull the clutch cable, or it engages? And if I don't tighten it down crazy, it spins on it's own, but then I put the cover on, and it won't engage with the clutch lever, or it will barely. The arm on the cover will bend out farther than I've ever seen it.
This is ridiculous cause I've built this engine like 4 times and never had a single issue with it. Now I'm going nuts.