Echo SRM 225 will not run

I have verified carb, ignition, fuel lines, air and fuel filter, plug are all good, compression is 50 psi 1st pull, 75 psi on 2nd pull, and 90 psi on the 3rd pull on the starter rope. I can get up to 110 psi by 6th or 7th pull. It will hold the pressure for a hour with no leak down. Please tell me what I am missing.