aaron it may pay to get someone to check the fuel lines attached to the tank especially if the boat is a few years old they may have perished and cracked at the tank?

When you park the boat is the boat angling up at the front, in other words bow high, or is it bow low, i.e the jockey wheel screwed all the way down.

If the breather outlet from the tank is below fuel level, the fuel will expand and vapour will be created inside the tank. The resulting pressure can only be relieved via the breather, which I suspect is below the fuel surface, and so fuel instead of vapour will be pushed out the vent.

Have a look at the vent outlet on the tank, it should be at the top front, but it could be mid or rear of the tank. The breather should be at the highest point in the fuel tank. Whether parked on your driveway, or out on the water.

Hi mate I had the same trouble the other week. I was filling it up at the servo and said to my brother in law cant ever remember costing that much, so I stopped. So I launched the boat and we took off. We both looked at each and could smell the fuel. Any way took it back home and removed a bit of the floor and tightened all the worm drive clamps up, but at the top of the tank the hose fell off due to a stuffed clamp. Replaced the clamp and good as new. Mate I would try all the basics first and no luck then have a look at getting the tank tested.

Gday Aaron,

Mine does the same too. Especially on a real hot day the fuel seems to piss out.

I think the breathers may be located on the side of the tank instaed of the top which will cause the problem.

And the breather outlets are lower than the filler which will just compound the problem.

I tend to fill my tank chockers. I think if I just filled it til the bowser clicked off it would be ok.

And like you I have my boat full and ready to go at the drop of a hat.

Anyway I hope you can clean up the pavers and keep the piece with your wife.

Tight lines

Terry 

Its caused by the expansion of the fuel during the heat of the day because there isn't enough space left in the tank to allow for it forcing it out the breather. The next time you fill it up don't force it in, let it burp once or twice but don't keep topping it up.

Google handy hints on how to remove fuel stains, there is bound to be someone who has an easy solution.

guys,

The tank is well below the height of the breather, some good 70/90 cm above. Top of the gunnels.  Breather is located at the back of the boat. The boat is only on a slight lean front to back but last week it was back to front.

The fuel lines were only just checked before i purchased it, some 3/4 weeks ago.

It has stained the side of the boat as well.

I will try load a photo.

I'm not talking about the beather outlet on the hull, but the connection at the tank, if that connection is below fuel level, either by filling the tank above this level, or the atitude of the boat causes this fitting to sit below the fuel level, expansion of the fuel and vapour pressures produced will push fuel instead of vapour out the breather.

The breather is a separate line from the tank to let the air out as you fill it and to let air in as you use fuel via the engine. Where you have filled the tank right up it has covered the breather outlet on the tank and when the fuel heats up and expands during the day its forced up the breather pipe and out on the boat and driveway. It cannot get out of the filler pipe because that is higher up and usually has a gasket on the cap to seal it so water can't enter and fumes and fuel can't escape.

Agree with Carnarvonite,my boat does the same i dont lose a lot of fuel but it sure looks like a lot when it runs down the side of the boat and settles on the driveway.Took me a while to work out what was happening so just stop the fill at first click on bowser and problem has all but disappeared only notice on real hot days. As insurance i always take out a 20ltr jerry just in case tho have never had to use it.