i rebuilt a s&s super e carb, im having a problem with it fouling the plugs i adjusted the carb to spec and i still foul the plugs,im getting black smoke after they foul,when i put a new set in it runs good for a lil bit then goes to crap,do i need to retard the timing a lil bit?someone please help me it is kicking my butt,if possible give me a processs of elimination,i am flat broke due to plugs lol also the front plug is black and the rear is brown,