I have gotten this mower of mine 2 years back when it was not running, I clean every nook and cranny and even replaced parts of the carb, and now the engine is running great eccept it burns a little oil. And yes I have adjusted the carb. Its running the best it can right now. No other setting makes it run better, only worse. Its allways fouling spark plug, and I have to sand blast it aftor a while to get it clean again. Since this thing is 16 years old, I know for a fact it is worn pisten rings. Believe me the carb is not the issue here, it is as clean as a wissle, and adjusted properly.