Motorcycle Repair: 83 shovelhead fouling plugs., shovelhead, valve guides

Question
QUESTION: I have a '83 shovelhead given to me from my parents. it was completely rebuilt after katrina. my father had an s&s super carb put on it and ever since then it has kept fouling the plugs after a short time of running.It has twice sent to a mechanic who said they knew what they were doing and twice they proved it wrong. need help!!  thanks

ANSWER: A couple of questions. Was the carb installed when the motor was rebuilt? When running, does the bike smoke?
Mike

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QUESTION: the carb was installed before the bike was rebuilt. when running at idle the bike doesnt smoke and when gas is applied small, barely visible, puffs of black smoke appear. it may simply be a jet problem, i dont know. when i ride, it just doesnt run smooth. this problem occurred before the bike was rebuilt.

Answer
The cause of fouling plugs can be three different things. One is a bad coil, two is oil getting past the valve guides or rings and the third is a carb that is not jetted right.
I would start by doing a compression test as well as a bleed down test. Then I would test the coil to make sure its good. Last, I would check the jetting on the carb. If you need to know how to jet it go to S&S's web site and there are instructions there for you to follow.
Good luck and happy riding
Mike