You might try using a JIS screwdriver and very gently try to tighten up the screws first. Run a strong dose of Lucus Deep System Fuel Cleaner/or Seafoam in the tank (3 or 4oz) and drive it. Personally, I use the Lucus for bad problems and the Seafoam for maintenance from time to time. It could be a bad gasket though. I would try tightening it first.