Try putting your finger over the exhaust outlet while you are turning the engine over with the EZ-start, you should see the fuel going into the carb a lot faster than when you just turn it over.  If this is the case, your fuel system is probably sealed up good.  If you don't see the fuel rushing through the line when you do this check your fuel tank for cracks, the fuel and pressure lines for and leaks and the tank o-ring for a bad seal. You can take the tank off and put it under water while blowing into the pressure line with the outlet capped off to see if you see any bubbles.
You may want to clean the carb again and put a filter inline before you try to start it again in case there is some junk floating in the lines (and replace the lines as well).
Also, sometimes the factory settings don't work for the environment.  Try going 1/2 to 1 turn richer on the LSN to see if it will fire up.  When it's cold out these motors need a lot more fuel to get going due to the dense air.</p>