I have a 1947 1/2 ton pickup with a 1959 235 engine. The carburetor is a Rochester one barrel. If I start the engine as often as every few days all I have to do is turn on the ignition key, pull the choke out and hit the starter button and it will fire right up. BUT, if I let it sit for a week or longer and go through the same steps it will not start. It just continues to turn over and doesn't even make an attempt to start. Then, I pour about 3-4 ounces of gas into the carburetor throat and it will fire right up and run as expected. I thought I might have a fuel pump problem but if I did it would stop running as soon as the gas I pour in the carburetor is burned. Also, when running the exhaust discharge is as black as a bowling ball. I have been told this is because the carburetor is set too rich. What say you folks?