This is in the clutch case, where the flower nut is?I’ve the big gear is turning the small gear but the piston isn’t moving remove the small gear and check that key, your kit should have come with a puller to take the gear off.
Is this normal? How there is a black piece just hanging? Got it on the other side tooThose are normal rings.
Here's a Zeda triple 40 piston, new out of the box. Those pins go on the carb side of the piston. You should be able to compress the rings to fit the cylinder on over them.
No matter what I do the head will not go backThat's all normal. That's the wrist pin clip that keeps the piston on the rod. Center the ring gap over the pin in the groove, squeeze the ring together and push the piston down over it. Repeat for second ring.