While your tank is off for inspection it is a good idea to de-rust the top
of it. Crud gets up there and eats away ant the metal.
Seals....There is a large rubber seal that goes round the filler neck and
several small seals that seal the pipes that go to the expansion tanks in
the wheel arches. FWIW I had your same symptoms and it turned out to the
end rusted off a thin metal pipe which runs along the top/side of the tank.
Cut it back to good metal, cleaned it up and connected to up with new fuel
line pipe. All is now well.
Good luck with it.

Martin

At 16:59 06/03/00 -500, Ezra Hall wrote:
>  Since purchase last Sept, we have had a gasoline smell problem after
fill up,
>especially when filling the tank all the way. I see the filler neck leaks
towards
>the opening, so that needs replacement or repair. However, even after driving
>for a couple of hours, gas can be smelled when the doors are opened. I assume
>I need to drop the tank to find the source of the leak. I would like to
minimize
>down time, are there common seals that need replacement so I can order prior
>to dropping the tank? Hopefully we don't have rust holes on the top of the
tank...
>Other than the filler neck, there are no visible leaks from below.
>Thanks,
> Ezra Hall
>www.together.net/~ehall
>'88 westy, Automatic
>
>