water in gas tank

[herbonbay]

I've been having a problem keeping water out of my gas tank. I have a 19 ft Scout flats boat w/ a 150 hp Yamaha 2 stroke. I'm fairly certain that the water isn't entering the tank from the exterior and that it's all simply from condensation. The boat has a 52 gallon tank that sits under the desk in full sun all day when the boat is in the water, which is all summer. The bottom of the tank sits against the bottom of the hull, so it's understandable that some condensation would take place. I've drained the tank twice, but don't think I've ever managed to get everything. I use a fuel/water separator, but at the end of last season it was filling with water after a weeks use. Has anyone had a problem of this nature, or better yet a solution? Does anyone know of a product that will effectively remove the water from a contaminated tank?

Regards

[jwalker]

It does sound an excessive amount of water. Filling the tank with fuel before leaving the boat will ensure most of the air is expelled. You will have to leave enough room for the fuel's expansion though. As to removing the remaining water; alcohol is miscible with water and it also burns. In the UK the easy source would be methylated spirit (methyl alcohol) which is widely available for various uses including camping stove fuel. You probably have a similar source. Methanol can be used too. I believe you have road gas which is a methanol mix. It is not usually recommended for boat use because it attracts water and there is the resultant corrosion problem. However, it might be worth a couple of tank fills to attempt the water removal.

Good luck. Let us know how you get on.