Earlier this year, I replaced the gas tank on my 2006 9'er. I did not notice that, despite my best intentions, I had received a shiny new non-California tank. No big deal, except the gas cap does not have a vent feature. Somehow, i made it for months only getting a little vacuum or pressure on the tank.
Well, lately the problem got bad enough to make me really worry for the tank, and I figured out the above situation. I took the gas cap apart and provided a tiny hole to allow the tank to breathe, and the vented gas goes through the same little port on the side that was (almost) provided to do so.
Now my question is, what does the seal look like that goes between the top of the tank and the non-California gas cap? Online catalog drawings are too crude to see how it all works.
If someone could (please?) post a few pics of the top of the tank (cap open) and the underside of the stock cap, that would be really, really useful.