Black soot out of tail pipe

When i start my car black soot comes out of both tail pipes and gets on my garage wall. It will dust right off the wall with a rag.

what could be the cause of this?

Bob,

It most likely means that your air/fuel mixture is too rich. Do you have the correct carburetor on your car? The reason I ask is there is a guy in our club whose car does the same thing and he has a different carb then the one that it came with from the factory. I would also suggest that you take it out on the interstate for a long drive. That should help blow some of that carbon out.

Regards,

While Lew is correct, as usual, it could also be the automatic choke is out of adjustment. We tend to forget that old cars need seasonal adjustment of choke and idle mixture. If it only happens on warm up, and since it dusts right off, you might check the choke, no matter which carb you have.