Craftsman snowblower only runs with choke fully open
I have a craftsman 2 cycle snow blower that starts up fine but when I turn the choke off it dies. If I leave choke on it will stay running for a while (15 or 20 minutes) then will start to die out. If I press the primer button as it is dying it will prevent it from shutting off and will continue running for another few minutes. I have fresh gas/oil mixture in it and proper ratio,I have cleaned the plug, and cleaned small air inlet on carb (small brass colored pipe), I have also cleaned carb. What's wrong and did I miss anything that I should have done?