Driving to cruise night in my stock '52 4400, all of a sudden it sputters and almost was underivable Black smoke and the only way I could make it home was to rev the engine at a high idle. I pull the plugs and clean them, check the ignition and found nothing. Played with the idle screw and even turning it al the way in, no change. So I think it was a internal leak. Oh ya, main jet vibrated out and was sloshing around in the bottom of the carb. Reassembled and installed and as good as new. The engine vibration at cruise speed must of jarred the jet out.First repair that cost me nothing but time.
