I have a Poulan 3400 chainsaw with deteriorated fuel lines. There are two lines coming out of my tank, both are bad, there is no question about one, it goes to the carb. The other goes over and back of the tank to some place i can't see. I suspect this is just a vent line but I don't know for sure, it was attached to a little nipple fitting at the top of the tank but there did not seem to be anything inside the tank attached to it. It looks like I would have to pull my flywheel to get the tank out to see where the line goes so i hope someone can enlighten me.