I think you have a couple of things going on at the same time. You state that your plugs are sooty. So your motor will fire up and idle, but the soot on those plugs can really interfere with the plugs ability to provide an acceptable spark under load. The rub is that something is causing those plugs to be covered in soot. I would fire it up and check for vacuum leaks. Also, confirm that the diaphragm in the vacuum advance is not ruptured. Get a little piece of brake line and some rubber hose, install it into the vacuum advance (with the motor not running), and blow through the hose. If you can blow through the hose, the advance is shot and will need to be replaced. if you cant blow through the hose, try turning the distributor first and see if it springs back. If it does, apply some vacuum and see if the advance will move the distributor. If you cant get the vacuum advance to move the distributor, its either jammed or frozen and will need some tlc. Might be the source of the problem. If the vacuum advance is ok, I would check the point gap and then check the timing. the other thing that may be an issue, but will require a little bit of tearing apart, is whether the mechanical advance in the distributor is free and working. I just recently rebuilt a 2403 distributor where the spring for one of the advance weights broke off and jammed under the advance. That and rust froze the weights and so the advance was inoperative. You have to take the point plate off the distributor to check as the mechanical advance is under the plate. Next, I would remove the plugs and do a compression test. Spark plug wires would be next on my list to check. Clean the plugs on a plug cleaner, regap. All low hanging fruit but easy to check off the list. If still sooting up the plugs and running poorly, I would think your next move would be the carb. Give it an adjustment and see if that makes a difference. Just keep in mind that these original carbs are pretty old now, rebuilt by who knows how many different people, who knows how many times, with who knows what skill, on a carb with who knows how many miles. It may just be that your carb has reached the end of its serviceable life and needs something more then a basement rebuild (throttle shaft bushings, warped body, frozen power piston, bad ball checks and seats).
Btw, any chance the stuff out of the tail pipes is just sooty condensation?
Last edited by Dragsix; 11/05/2018 3:11 PM.
