The adjustments on these Ice Makers usualy only adjust them a small amount one way or the other if they are overflowing a part has failed in the Ice Maker, and most of the GE Ice Makers are modular and have to be replaced as a complete unit the GE-TBX22RF You supplied does not come up could You give the model number to Your appliance and I can find an Ice Maker for You.
Now that I know which ice maker Your trying to fix I am going to have to suggest getting rid of it they discontinued these along time ago and I honestly never expected to ever have to deal with them again, not to question Your ability but are You certain it is overflowing because these are infamous for the piston seals leaking here is a kit for the seals and pistons>
But I will HIGHLY suggest replacing this with a whirpool ice maker kit this one comes with connectors to fit Your refrigerator>
Let Me know which direction You want to go and i will do My best to aid You
Fair enough I regret to say that I havent seen one in a while and I cant find any thing on the adjustments, and I refuse to give information I am not certain of.
Best of luck