OK, I see now that inside the spark plug cap, there is a little spring that is supposed to hold the cap on the plug. On mine, that spring is shot, so the it wasn't making good contact. I wrapped the wire from a twist-tie around the end of the plug to make a better contact and that seems to have done the trick, but it is still totally erratic and I think I have a fuel delivery problem. I can see the fuel through the new see-through lines and filter I installed and there are all sorts of bubbles and when I dump the carb bowl (using the petcock on the bottom) it doesn't refill except very very slowly. I am not sure what the problem is because the petcock on the bottom of the tank seemed to flow fine. Maybe the needle in the carb is not letting gas in? Except before I installed the carb I made sure that the float and the needle were working well together and there were no restrictions.
Until I know for sure that fuel is flowing good, I can't get to tuning the carburetor. This is driving me nuts. I guess my next step will be to unhook the fuel line from the carburetor and run it into a bucket to see if it is flowing good.