Merc 2.2 - keep finding water in the fuel

[gandy]

Hi,

Generally the Merc 2.2 on our tender runs sweet as a nut (touch wood) after I replaced the float valve and the seal on the filler cap last year.

A recurring problem is finding water in the fuel. When this happens the motor won't run above fast idle without cutting out, or won't start. Drain the carb and there's water in the fuel. Run some more fuel out and in most cases there was no more water to come.

I'm struggling the think where it could be coming from. When the engine's not in use I keep the breather on the filler cap closed, and it doesn't leak fuel when the engine's tipped up. Could water be getting in while its running?

I know I can't blame it for not running on water, but I'm starting to hate that engine.

 

[yoda]

Remove all fuel from engine and fuel can - dispose of it in an environmentally friendly way! Start with new and try to keep the engine toped up when leaving it for any period of time to prevent condensation. Very unlikely that it can be getting in through any other route.

Yoda

 

[ShipsWoofy]

Mine too, one of the many reasons I did dump it, I lost all trust that it would get us home.

The night I decided enough was enough was after having to scull up river against the 2kt current, when I got to the slip I near collapsed in a pool of sweat.

It had a good run mind, over 10 years of abuse I would guess. But I had spent too many weekends stripping the carb down or cleaning the plug on the slip to get out to the boat.

It is now in the back garden looking for a home, if it is wanted it is erm, free.

 

[gandy]

[ QUOTE ]
Remove all fuel from engine and fuel can - dispose of it in an environmentally friendly way! Start with new and try to keep the engine toped up when leaving it for any period of time to prevent condensation. Very unlikely that it can be getting in through any other route.

Yoda

[/ QUOTE ]I did that last year when I first saw this prob. Drained carb and fuel tank, and my fuel can, and dried them all right out. By the time I'd finished the fuel system was clean enough for the space shuttle.

A month or so later, water in the fuel again. I don't keep the fuel tank full, but I had assumed that shutting the breather would prevent significant condensation - the air actually trapped in the tank can't possibly hold much water.

 

[lw395]

Water can get into the carb as condensation in the airway of the carb, the carb cools as fuel evaporates and water condenses.
Either store the motor somewhere drier, or drain the carb regularly.

 

[Lakesailor]

After a warm day as the fuel tank cools it will draw in warm air which cools and condenses out the water vapour in the tank. Always shut the breather when not in use. I had terrible problem with this on both a remote tank on a Honda and a built-in tank on a Yamaha.
Warm air above a body of water will always be moist.

Also, have you discounted water in the fuel from the fuel station?

Try pouring the fuel into a demi-jon and letting it settle. If there is water at the bottom you can decant the fuel off it quite easily.