Thanks for all the great advice. Here's a bit more information: The reason I had to replace the hall sensor is becuase when I was troubleshooting why it would not start at all the other day I noticed one of the wires from the sensor was cut, most likely by the "sleeve" I put over the wires to protect them. Somehow while messing around with the plug, etc, I must have tried the ignition ungrounded, and the hall sensor went out. I ordered a new one from CH, and it came installed on a small peice of metal which just bolts on in place of the old one, so I am assuming that I did not change the timing. I also soldered on a new spark plug wire to the coil. The old wire had a carbon core and had just been pressed onto the coil pigtail. CH said to solder the new wire onto the coil pigtail, so I did , and it looks okay. I tested the ignition with the plug out and it fires every time I turn the prop shaft. I also regapped the plug, and maybe screwed it up? I'll try swapping out the plug and see if that does anything. The battery pack is fairly new and was right off the charger, so it should be fine. It seemed to take a flip or two more than usual to start, but did start up and idle well. How do I clean the screen in the carb, or maybe a better question would be where do I look for dirt in the carb?
Thanks again for all your help.
Sam