On my sons 90 it will not start vis the electric or kick start. If I pour some gas in the air filter chamber it fires right up and runs great. After it sits for awhile the same issue occurs.

It is getting fuel and I have cleaned the carb. What else am I missing? Any help would be greatly appreciated!  

check the intake boot, or it could possibly have an o-ring
Your 90cc polaris is made in taiwan for polaris and some of these have the cast aluminum bolt on intake with an oring.
also check the air filter boot to see if it is leaking.
check the carb cap to make sure it is on tight.
you may have to break down and try to tune the air/fuel mixture.