One side is lean, one side is rich

Hello guys, So I got my motorcycle running and now I am fine tuning it. But when I take out the sparks plug, 1 side is running leaner than the other side. what can be the cause of this?

Have you tried balancing the carbs. The carbs are balanced in pairs first. Right pair, and then the left pair. Then you adjust the pairs together. I use a Morgan Carbtune. www.carbtune.com/

What jakedude wrote may be wrong or it may be right; it depends entirely upon which motorcycle you have. You really need to add the year and exact model of your bike to your signature line, otherwise the help you get may be bogus. As an example, the information jakedude provided is totally false for my 1977 KZ650-C1. The Mikuni carbs on it are not balance in pairs. On some other models they may be balanced in pairs. In fact, as far as we know your bike might be a twin with only two carbs. Help us help you. Ed

Yes I do have 2 mikuni carbs. I have to tune them individually. My bike is a KZ400. I just want to make sure that it is not a timing issue. But simply a carb tune or something.