Originally Posted by grizz1

Hi El Tigre - Take your fuel tank out. Make up a plug with a small piece of fuel tubing bent over itself and clamped together using a small cable tie (also handy for plugging the fuel nipple on your engine when it's out for maintenance etc).
Put this plug on the nipple that comes out of the tank itself. Connect a length of fuel tubing to the pressure inlet nipple on the tank lid.
Now fill your kitchen sink (best do this when the lady of the house is out of sight ). Place the tank entirely under water and blow into the fuel tubing connected to the lid. If any bubbles come out of the tank you have a leak.
Most common places are around the sealed edge where the two halfs of the tank are joined, or from the lid due to a faulty "O" ring or a weak spring. If in any doubt, replace the tank. They are not expensive and it's safer than trying to glue up cracks etc.
Be sure to thourghly dry the tank off and flush some fuel through the tank before using it again. You do not want even a hint of water mixed in with your fuel.