Yep I think that is what is happening, like I said there was no fuel in that line when I took it apart, now to start it I'll have to pour fuel directly in the vent on top of the carb. I want to fix this, take it out fo r a drive a measure how hot things are with my infrared. There seemed to be fuel in the fuel/separator which is good. I don't know if the line on the heater hose would be the whole contributor to the fuel boiling though?