Clutch/engine seized cylinder head won’t come off

[Toby woodman]

I have a new 66cc engine kit. While I was riding it, the engine started clicking and then Stalled. When I tried to re start it, the clutch started slipping. I have cleaned and de greased the clutch pads and adjusted it but it still slips and the engine won’t turn over. When I go to take the cylinder head off, only the main cylinder wall will come off. Help would be appreciated. If you have any questions ask and I can also send more photos. Thanks

 

[Wrench]

okay. how common is this for just over 3 hours of runtime. is there anything I can do in the future to stop this from happening with my next bike

open her up and replace the wrist pin clips with quality clips

 

[Chainlube]

when slowing down with the engine at idle and the clutch lever out. I head a knocking/clicking noise. could that be wrist pins or could it be something else like running the engine too lean. could someone have a look at the picture of the spark plug?

If you run it too lean, that will cause it to over heat, when it over heats things expand real fast and then all kinds of trouble can happen.
The ring spacer pins are steel and the piston is aluminum, the aluminum expands faster than steel and the pin can come loose.