MECHANIC: How to fix a flood on a weed-eater?

it leaks around the tube and the nousle of spout wher the gas goes into the carborator from the gas tank and i not sure of a way to tightin it on it and will that cause the whole motor to not run and make the spark plug wet from the gas it has compression from the piston and how would you tell if the spark plug works or not by looking at it