I have a Toro model 38584 snowblower, it had a problem staying running. I replaced the fuel line and took apart the carburetor and did a through cleaning everything with carburetor cleaner. Dried everything off and reassembled it, then reinstalled the carburetor and filled the fuel tank with fresh fuel. After several pulls it started, ran very rough but, smoothed out somewhat but once it warmed a little it wouldn't idle on its own without me pushing on the primer, once I stopped it would quit running. My question is; what could be the problem now?