eagle flyer1

Antique. When i start the engine at factory settings it starts (5600 rpms)but quits shortly after it starts, I have tryed to lean it out 1/16 of a turn at a time but it never stays running and only gets hot from not enough fuel(it never goes up in rpms). So i put it back at factory settings then richie it out 1/16 turn at a time. When i get to about 1 3/4 turns it gets up to about 6100 rpms and stays running. Then i can turn it up to 2 or 3 turn richer and it doesnt do anything different. Doesnt go up in rpms or down in rpms. It also never boggs down from being to rich. So i clean out the screens and it is no better. I am calling Cemark tomorrow to see if it is a bad carb. or not. And ask them what to do. It is a 3mm Toc 50cc engine.