Idle acting crazy

I have been messing with the car all week. I have adjusted the fuel mixture screws & the idle a bit. I also had a possible vacuum leak since 2 of the carb bolts were loose. None of the carbs or gasket kits come with lock washers but could I use lock washers to help keep the carb tight? Or do I need to just get in the habit of checking them regularly? I will post if I have things ironed out or if it keeps happening. Thanks for the help.