butterfly and linkages moves freely. the engine only idols. when adjusting either the low or high adjusting screws it will die. I am just as confused as you, I am a former mechanic ( retired ) the only thing i can think of is either the new fuel line is to small. ( i.d. )or the carb has plugged passage. ?? no cracks evident on carb or intake plate. butterfly and linkages moves freely. the engine only idols. when adjusting either the low or high adjusting screws it will die. I am just as confused as you, I am a former mechanic ( retired ) the only thing i can think of is either the new fuel line is to small. ( i.d. )or the carb has plugged passage. ?? no cracks evident on carb or intake plate.

What model is it that you have.? Did you replace it with genuine fuel line? Have you checked that the exhaust isn't coked up.? What's it run like if you remove the air filter and partially cover the carb venturi with your thumb.? What model is it that you have.? Did you replace it with genuine fuel line? Have you checked that the exhaust isn't coked up.? What's it run like if you remove the air filter and partially cover the carb venturi with your thumb.?