HuaSheng 49CC drive problems

Hello people, I'm having problems figuring out a 49CC HuaSheng motor, or more specifically the drive.

The chain jumped the rear sprocket and tore stuff up. On the transmission, you can feel the damage to the bearings.

My problem is: Having everything, I think, back to original position, the flywheel/clutch turns and makes contact with the bell, the bell turns, but it does no turn the sprocket to drive the chain. I think I see what might be a key holding the bearing to the shaft, but just don't know.

Also, on the black cam, I'm wondering what might be inside this except the two bearings. There may be something inside broken I guess??

Can anyone give me some clues on this. I've been spinning my wheels working on it, and really need to get it fixed so I can get my loaned car back from my brother.

Thanks for any help.

Gary

If I can figure out how to post pics, I will as soon as I get my 2 cycle's mount holes fixed. Thank someone for Helicoils!

I have uploaded several pics, but they really do not show more than where I believe the problem to be.

I just found my snap ring tool, and will be able to pull the bearings from the shaft in case there is something inside more than the shaft and two bearings. I don't think there is more inside.

I do not yet know how to view the pics I uploaded.

Yes, it is the 4G from Grubee.

As I said, the bearings are grinding and that at least needs to be fixed. I do not wish to buy a complete transmission (is it a tranny or gear reducer?) for it if I don't have to.

I'm taking a break after repairing threads on my 2 cycle, and am going for a nice long ride today. It's been one thing after another, and have not been on a ride further than about ten miles all summer.

I appreciate the responses to my questions, and hopefully I can get this thing going for little brother.

Gary