Motorcycle Repair: s&s shorty carb with sbd pipes, el bruto engine, plug wires

Question
QUESTION: Hi. i have an s&s 113 cu el bruto engine with an s&s shorty carb. the bike has an
sbd 2 into 1 adjustable pipe. At idle, the bike seems to run rough. The plugs
look black. The bike seems to run better away from idle.  Are the pipes the
problem? Will leaning the idle mixture fix things? Thanks for you help.

ANSWER: Did this just start or has it always been this way?
Mike

---------- FOLLOW-UP ----------

QUESTION: i just got the bike, and it came like this.

Answer
Without knowing how the bike ran before you got there are two ways you can go. One is test the coil and plug wires. If they are weak then you will have the above problem.
the other way is the carb isnt jetted right.
I would test the coil and plug wires first. If they pass then rejett the carb
Good luck and happy riding
Mike