Motorcycle Repair: Harley carb tuning, intake leak, carb tuning

Question
QUESTION: Hi Mike, I have a 94 1200 Sportster with a stock cv carb. I have an unusual problem. When I'm riding the bike, it will cough when at a steady speed. It doesn't matter whether it's on the street or at highway speeds. It only happens when holding the throttle at a constant speed. Runs great other than that. Any ideas ?

ANSWER: Pull your plugs and let me know what color they are. Are there any modifications made to the bike like exhaust, cams, high flow air cleaner?
Mike

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

QUESTION: Bike is bone stock. I put new plugs in it before every riding season. Only have 2500 miles on them. Pulled them and they are light brown, the electrode isn't burned off and they aren't oil soaked at all. Could this be a jet problem ?

Answer
First thing I would check is to see if you have a intake leak. You can do this be letting the bike warm up and then spray a little carb cleaner around the intake. If the RPMs go up you have a leak.
If this does not stop the problem then I would install a Dyno-jet carb kit. This will give you a little more power, give you more throttle responce and will probably solve the cough
Good luck and happy riding
Mike