48 Ford running rich.

[Old26Buick]

Tail pipe is real black. Engines runs good, Could it be too big of jets in orginal carb.

[19tom40]

Could be wrong jets or drilled out jets. Could also be float level or power valve leaking.  Could also be black and sooty from excessive idling. I believe that the model 59 carburetor came with .050 jets for most of the country and .051 jets in the mountain areas.

 

Check for fuel entering venturi while idling at 450 rpm. If any fuel is seen, check the float adjustment. If the float is in adjustment, replace the power valve.

 

If there is no fuel entering the venturi while idling at 450rpm, your jets are the most likely suspect.