Re: Location of Carburetor Vent on 1973 CI
If providing tank venting doesn't solve the problem, the first, I'd disconnect the fuel line and let it drain into a container. If the fuel runs out in a stream, not just drips, and continues until the tank is empty, then the issue is somewhere "down the line".
Check for a dirty in line fuel filter, or old gas line that might be swelled or collapsing. If it is old line, suggest replace all of it. Cheap to buy at an auto parts store.
If it has a fuel pump, you need to test that flow too. Frankly, small cost of replacing a fuel pump is probably worth it if that is an original or is old.
If fuel still flows well into the carb, then the problem is inside the carb. If it originally had a dry bowl when you first checked, I'd say maybe you have a faulty or sticking needle valve or a clogged passage somewhere internally. Disassembly and a good cleaning will likely solve the issue.
Just some thoughts on what could be wrong. Good luck finding out what is wrong with your particular machine.
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