I re-tuned my engine on the bench recently. As was suggested, I needed to lean down the idle mix a bit, causing smooth transitions. Havne't yet had time to fly [college student] but I'm optimistic. However, the carb screws vibrated loose and fell to the ground. Anybody have any reasons for this? I'm probably going to use lockwasher/nut and locktite for the next set of screws.