2 stroke 50 Breaking Up real bad
 

Low to mid range power, it runs like a champ, Wide open on a stand or down a hill, it will start popping and breaking up real bad, and if I don't let off the throttle it will bog down and die. Scary. Anyone know what's up?

Try a larger main jet . It has limitations even after tweaked

Aye! It was indeed the jetting! I had drilled a hole in the exhaust for better flow, and didn't match it out with fuel, nor tuned the carb to the change. Thanks!