Know of any containers that don't leak at the spout when pouring fuel into tanks? I find the new type spouts kinda combersome to use. I have some old cans put can't find new spouts. A 3 gallon size works better for me.

take a llok at the washers in your spout. sometimes they stretch bad from the gas touching them. i have a hedge trimmer that you can't seal the lid on for nothing. a boy helping me said he always puts a piece of plastic bag over it and that worked. maybe a little wrap or two of some of your wifes saran wrap cut into a strip would work for you, sort of like teflon tape on a pipe joint.