stopcock/intake vacuum line

[John Jordan]

What is the cause for the intake to stopcock vacuum line to get moisture, (fuel), in the line while running? Is it coming from the stopcock leaking through the diaphragm, from the intake nipple due to to rich of a gas supply through the carburetor,? The exhaust is very rich! You can see the unburnt fuel, gray smoke, in the exhaust as well as the strong smell of unburnt fuel.

Please advise.

Thanks for any advice on possible cause and or remedies for this problem.

John J.