Others might disagree, but I would either pour a little gasoline down the throat of the carburetor (careful!!) or spray some starting fluid in it. My '51 is little-used, and when I try to start it every couple weeks, and it doesn't start, I wonder whether I've broken something in the course of other work. So I give it an ounce of gas in the carb, and assuming the battery is charged, the connections are clean, the choke is closed, etc., etc., it starts up.
