Just take the carbs out and clean the hell out of them.
No u don't. If u take them off and don't touch the sync screws, then it stays the same and u don't have to sync it but it doesnt hurt to sync it anyways.Try running some SeaFoam through the system first. It's cheap and easy and may fix your problem. If you fully remove the carbs they will need to be synced again. Do you have a service manual?
Yes u should sync them but taking the carbs off doesnt mess up the sync.And how would you know that they were synced properly to begin with? After a carb clean I would certainly take 20 minutes to properly adjust the carbs.