Check you water level in your battery if it's low top it up with distilled water or some other form of purified water.charge it up fully and take it to any shop auto or bike and have it load tested.It may be just it's time.
As for the carbs being out of sync it won't effect start up unless they are grossly out.
As for the carbs being out of sync it won't effect start up unless they are grossly out.