Join Date: Apr 2009
Location: Gloucester, Va, USA
It wouldn't hurt to re-sync the carbs. If it's just a small difference, and the engine is running fine, I really wouldn't worry about it. The gap maybe a little off on one or both of the plugs. I would imagine that even the index of the plug (read: the way the electrode points) would make a small difference in plug color.
If the bike has over 1000 miles or so on it, and the carbs have never been re-synced, I would say that a re-sync is going to do it. The initial service on the bike calls for the carbs to be re-synced.
The carb work during the first service, from what I gather, is really the only critical thing besides the oil change. Every bike tech I talk to says that the valves are almost always in spec, but the carbs almost never are.