Carbs won't stay synched , Why ?

Hey guys, I've synched my carbs several times now and after riding for a few days. I notice that one or two arent synched as they were a few days before. Why ? It isnt the same carbs either, one day its the right carb or #1 , then its #2 . I'll synch # 1 and all is good, then # 2 goes out of synch. Synch that one up and good for a few rides more, then another carb goes out. What am I doing wrong here. Im sure Im getting everything tight when im done synching. Wayne

which bike it is on. If it is the C2 and you are using the original carbs. The only ways I can see it happening that quickly is the holes on the levers are worn and they are rotating slightly on the cross shaft. There is wear on the linkages that go from the levers to the pistons. The linkage is catching in the slots for the adjusters, or possibly the springs inside the adjusters are weak or assembled wrong if they have ever been apart.