Rich running engine

[randall1234500]

I just purchased a restored M38A1 and it had a Solex carburator. Never could get it to run correctly.....Always ran too rich. I purchased a NOS Carter and installed it....Now, it runs and starts better, but, I still think it is running too rich. When ideling, it has black smoke out the exhaust. Normal speed ( 30 - 40 mph ), it seems to run normally. I have adjusted the idle screw....Anyone have any ideas the problem.
Thanks,
Randall

[wesk]

Since you said the carb is NOS then it's a strong probability the rubber diaphragms in the accelerator pump and metering system are the old type material and are deteriorated. Remove the two small square vacuum chamber covers (4 screws each) and check their condition. Also check to see the springs are installed correctly.