Also could depend on the temperature of your plugs, if they are not running hot enough then they will not effectively burn off the carbon, and if they are too hot they burn out and in some bad cases can cause pre-ignition. So if your engine is custom or has a different cam, carb, headers etc it might be a good idea to look into what plugs you should get, compression pressures also affect this. But if no mods have been made then just clean up the carb and go for a good ride, should get it hot enough to clean it up just as was said before.