Henson,
I've got a stupid question for ya. Will it re-start after it quits? Or do you re-fuel and start agian? The reason I ask is that you may have the fuel lines reversed. Could be once the fuel is sucked down past the (what is supposed to be) the vent line it quits. Hate to admit it, but it's happened to me. Fought a Fox 19 and finally got fed up and was going to replace the engine when I found my goof.