Many things can cause a rich cylinder. Stuck closed choke plate or carb crudded up or maladjusted is a likely cause, plug cap resisters corroded, or even a bad plug are also possible. Can you smell gas or notice any dripping at below the carbs? The key is to deduce which of the simpler possibilities to chase down first. How about a little more info? Did this condition suddenly appear on a daily rider? Or was the bike just brought out of an extended dormant period (more than a year or two)? Done any recent work on the carbs? Is it running okay at higher rpms? Seem to have a normal amount of zoom zoom? A lot of input is helpful to limit suggestions like "lap your valves" when all it needed was new spark plugs, eh? Also, since "we" don't know anything about your capabilities or mechanical experience, don't be offended if some advice borders on the real simple stuff you may have already covered yourself. Help us get to know you and your bike and you'll get plenty of advice here. And we're a nosy bunch, soooo, where are you from? If you're near Sacramento, CA, or Appleton, WI, you just hit the CX/GL jackpot . . .