Yes I've checked the head tourque I've changed the rings I've done all I can think of spark gas so all that is left is compression. I think it was the air filter problem.
You're making it kinda hard to help you, I mean, do you have a motor to fix or not?
The first thing I would say is break in you motor well, with the proper gas mix and do not ride it wide open throttle for more than short bursts until you've burned through two gallons of break in mix. Second, run with the air filter ON. Third, add an inline fuel filter. Fourth, make sure your head stays torqued...
As for the compression, it should be pretty easy to feel the compression when you let out the clutch and/or feel the change if there is a loss of compression. Is this the case? Are the cylinder walls scored? Pistons burned? rings trashed? If you have a cylinder that isn't scored, good rings, a good head gasket and a properly torqued head with spark plug installed you should get compression unless there is excessive wear, it seems none of your motors ran long enough to achieve excessive wear...
Post pictures of what you got going on and maybe we can help you, otherwise, I just got an email that skyhawk motor only are on sale for $109/48cc and $119/66cc with free shipping at gas bike, if you want to just burn up another one....