I have lots of black soot which spits out the tailpipe.And my spark plugs get soot as well. Iam told this is due to too rich a mixture. Also was told this could have something to do with the car not able to drive more than 30mph.How do I adjust the carb to lean this mixture out.It seems that I get to a certain rpm and the 29 "fights" the acceleration.

What you describe is usually associated with a problem in the carburetor. Hang tight, and the carb man will be along and answer your question.

It could be the carburetor but also could be ignition or an air restriction. The only adjustments that you can make are to the idle mixture by the screw to add or reduce dilution air and float level. Otherwise it takes replacing parts to change the mixture.

Weak spark and low volatility gasoline will produce copious quantities of soot. So it is better to make sure it is not ignition before tackling the carburetor. What spark plugs are you using? What is the gap. Are you sure that the ignition timing is advanced enough. We have found that 0.040" spark plug gap and ~16 deg. advance is much better than the 0.025" and 12 deg. When you hold a spark plug (or coil center wire) ~ 1/2" from a ground and the engine is turned over do you get a spark that makes a "Snap"? Does the car accelerate well before it begins to bog down? Does it run rough or pop and cough at the 30 mph max?

Do you have fresh gasoline? Is there a restriction to the air flow to the carburetor? Is the choke fully off when the engine is running? Is the engine fully warm when you have the problem?

Those problems are generally much less expensive to cure than the carburetor. Quicker too.

Actually, the timing should be 18 degrees.