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I am having a fit with my 235 trying to get it tuned up. I have rebuilt my Rochester one barrel, replaced dist. Cap, Roter button, new plugs set at 35, went 1.5-2 Turns out on air mixture set screw. It starts but black smoke is billowing out the tail pipe and other one start the plugs are completely thick with black soot or carbon (all six of them). It has a real bad miss especially when I rev it up. Could any one tell me where to start to correct this problem? Any advise would be appreciated. Thanks.

Your carb is way too rich. Make sure the hole in the bottom of the carb has a passage way in the gasket to the intake vacuum. Make sure the float level is correct & the float does not have gas in it. Slowly turn the idle jet in till the engine starts to slow down. Then back it out just enough to speed it back up.

First time to rebuild a carb so here comes the newb questions, the kit came with 3 gaskets that all fit, I did see an indention in the old gasket that looked like it needed to be a passage way so I chose that gasket to use. So needless to say I'm not quiet sure which passage is the intake vacuum? Appreciate a little help, thanks for responding so fast.

You'll need a vacuum gauge to set the mixture. Set everything as per the book and hook up the vacuum gauge to a vacuum port.

Set the idle speed.

Check the vacuum gauge and slowly turn the mix screw shut and see if the vacuum increases of decreases. If it decreases turn the other way. Once you set max vacuum check and adjust your idle speed. repeat until you can get your idle RMP and the highest vacuum reading on the gauge.

The vacuum gauge should not bounce (steady needle or AT MOST a tiny vibration.. no pulsing or vibration of more than 1 tick on the face of the gauge.

Once set take you plugs out and clean/gap them. Fire it back up and double check the settings. IF it all the same you are done.

OK doesn't sound too bad, I'll give it a shot, thanks again for the advice.

Did it run good before you changed the base gasket style?

Hold the gasket up to the bottom of the carb. The small hole should line up with an indentation in the gasket. If not cut a chunk out of the gasket to form a passage to the center of the intake manifold. That is wear the vacuum is.