Check the seals on all the hardware, on top of all the tanks! When I picked up my 2008 Puma, it also had the same problem! It was found that a seal on the top of the main center tank, under the seats, was installed incorrectly and was leaking gas into the bilge! I would not run the boat, or charge the batterries until you have solved the issue. Extremely dangerous with the batteries back there. Also when you have identified the problem and fix it, flush the bilge with fresh water. If you didnt know, under the center seat or console, there is a access panel to the main tank. The fiberglass cover that the seats mount to, is also removable by way of a little effort and a few screws. If you need any help, contact me at: Jewalston@aol.com and I will be glad to help you! Be Careful!James