Re: engine help?
Your cylinder head is cracked? A crack changes it useful life into a paperweight.
Are you positive that it is not a bit of flashing left behind from the casting process during manufacturing?
If there really is air coming from the clutch area and you have narrowed it down to the clutch/ transmission shaft, that indicates that the crankcase center seam gasket failed in the small area between the flywheel cavity and the transmission shaft cavity.
This requires a total tear down of the engine to replace, so extra caution needs to be taken during diagnosis to be positive that this is actually the problem.
"It's a chinagirl. It's a sometimes fun little engine that often will break your heart. It's disposable.
Does not come with a fortune cookie."