Fittings
Your A-4 should have a hose running from the topside filler cap down to the tank itself, located under the starboard aft berth. When filling the tank, check for any leakage that might occurr only at that time. Like R.W. said, you will probably want to replace that hose.On the tank itself, there is a cylindrical cut-out that houses your gas guage. Check to see if the gasket under the guage has been replaced recently, or is of the "form your own" variety. My guess is that it is self-formed, or old, or both. This could account for a good bit of the fumes.Then, check all manner of hosing leading from the tank to the the engine. If these are old or even show remote signs of age - you know what to do. While you are replacing the hoses, you should install a water-separating fuel filter. It is very cheap, and will save you huge headaches.Of course, prior to all this, remove all fuel from the tank. When I did this, I got a 5 gallon gas can and placed it over the bilge. Then I removed the gas guage and stuck an outboard priming fuel hose into the tank. Put the other end of the hose into the gas can and squeeze the rubber ball to start a siphon. Do not attempt to use a pump to do this, as few are certified to pump gasoline and may explode. Make sure all hatches are open and that you have a wind blowing through the cabin, as the fumes will build quickly. I would let the empty tank dry for at least a day or two before installing anything else.If you have any further questions, re-post and I will e-mail you. Also, check the archives, as there is a good post in there about cleaining out your tank. Best of Luck -Rob