My Twister is hard to start when it's cold. I've been reading all the posts on "fuel enrichment" etc. I plan to try the bulb primer thing. I was thinking of using a small in-line bulb primer like they use on outboard motors.

Any thoughts on this concept? Would it provide too much fuel?

Before you do that, try pushing the pedal to the floor while turning the key for about 4 seconds, then stop, release pedal and try starting it then.
See if that works.

You need to turn your idle speed screw up to run in the cold with the stock CV carb.

You can turn your idle screw up to get it started, but after it warms up you'll definately need to drop it back down.
My DLX is very cold natured in NC. with the 130 jet, and turning the idle up will work but is a pain. If you hold the throttle open while turning it over, it fills the bowl up and that amount of gas in the bowl will allow for idle until the motor warms up and will maintain idle.