Have you tried using starting fluid? If you have, and it starts up with a couple of sprays, I would try opening the air/fuel screw a bit more. It may just be a little too lean on the idle circuit for your ambient air temp. 3 turns works fine out here on the west coast but we don't get nearly as cold of air temps as you guys do.

 

Well I got it started tonight, now the test is if it starts in the morning.

I charged the battery for about 3 hours, changed the plugs, adjusted my Fuel Mixture screw, & tightened up my air boot.

It fire right up after that.