My 70 140 has been a bear to start. She starts well enough in the morning as I have her in the garage (she turns over after a few tries, runs rough for a minute, and then good enough), but if she's outside all day in the cold it can take up to 10 minutes of cranking to turn her over. Even then she's really rough for another 5 minutes or so and I need to stay with her and keep an eye on her or she'll die. After that I can leave the choke out and let her idle get up to speed and she's good. Then she runs perfectly.

This has been a problem to one degree or another for a few months. When I got her she started up right away w/o trouble, but it was warmer then. Is this just the cold or another problem? If it's the cold, can someone explain why that affects it so? If not the cold, can someone point me in the right direction?

Starting fluid doesn't seem to help. I have the original Strombergs. Fuel pump works and gas is flowing.