Another No-Start

[nkaminar]

If the car idles better with gas off then there are two possible problems. Either the gas level in the carburetor is too high or the idle mixture adjustment is off, likely too rich.

You can get a tool that lets you see the gas level in the carburetor with the engine running or not. With the Zenith carburetor, the idle mixture jet controls the amount of air mixed in with the fuel. Screw it out and more air and leaner mixture. Did you try to adjust the idle mixture screw?

Here is a site that will help you figure out what is wrong: https://modela.org/symptoms.html