I've got a JD LX279 with liquid cooled 2 cylinder Kawasaki. It was running rough, seemed to be missing if I'm running over rough ground. I noticed some gas coming from the top vent tube. I took the carb off to clean it and stripped the main jet trying to remove it. I replaced the carb with a new one and it is also dripping gas from the top vent tube while running. Obviously not a carb issue. Is this an issue with the fuel pump? Attached a photo of the type of fuel pump it uses.