Jim,

""When the engine is cold (and the temperature switch is open), power to the choke flows through the resistor, making the opening rate slower. Once the engine wams up (and the switch closes) full 12 volts is applied to the choke heater.""

That is a great idea. I am fighting this right now in the cooler 45-50 degree outside temps. If I set my choke at #3 (3 marks from the back), it is too rich to start. If I set it at 3 marks from the front, then it opens too quickly and with the carb set leaner now (14.2-14.4), it is a fight to keep it running long enough to get some temp into the motor.
I am going to test a couple more positions on the choke and maybe a larger primary squirter and see if I can get the startup a little easier in the cooler weather. If this does not work, then I might get with you on your change. I am hoping that I won't have this much cold startup problems once the outside temps go back up.

Thank you.