Advantages Of A Single Fuel Tank?

[markpierce]

My single-engine boat has four fuel tanks; two on each beam. Need to switch tanks every eight hours or so.

 

[diver dave]

My single-engine boat has four fuel tanks; two on each beam. Need to switch tanks every eight hours or so.

Thats only 3 tanks less than a 707. [emoji847]

 

[SteveK]

Both engines cutting out within minutes of each other will make you sit up in your helm chair a little straighter. Gee wiz. You would've thought the racors woulda stopped the flow before the float bowls got contaminated...maybe gas is different.

I think if you suck in enough water, it's possible to just pull it right through the filters once they're full of water, at least with gas.

I sure hope not as that is one reason to have those filters. I can see the engines stall due to lack of fuel.

 

[diver dave]

Fuel filters rely on water coalescing and falling to the bottom due to differential specific gravity. The individual molecules are not blocked, right? If nothing but water shows up, the pressure delta will let them thru, correct?

 

[rslifkin]

Fuel filters rely on water coalescing and falling to the bottom due to differential specific gravity. The individual molecules are not blocked, right? If nothing but water shows up, the pressure delta will let them thru, correct?

I think the filter media is also designed to be water repellant. But yes, I'd expect if it feels it only water then some amount will get sucked through. Of course it won't be much before the engine stalls.

 

[boomerang]

On my diesel boats, when the filters got dirty/water in them the engine would run like crap with reduced RPM,s but the water never went past the racors. Same thing with the gas boats I've owned; I don't think any contaminates ever made it past the filter to the carburetors. On my skiff, I have a fuel injected 115 yamaha outboard. It has a spin-on filter and, if it gets super contaminated (I never have been able to keep the tank free of water; I think it gets in through the vent on the side of the boat) it does allow a little water to get past to the primary filter under the hood of the outboard , so much so that the motor wont run. The little plastic onboard filter with it's plastic mesh definitely stops the water from getting to the EFI system, thank goodness.

 

[Portage_Bay]

Water CAN get through a Racor filter. It doesn't need to get to the point of the bowl being full of water.

This may have been due to old filter elements. It happened on a delivery of a boat that hadn't been run in a very long time. When we got to rocking and rolling north of Pt Conception and stirred up the tanks the water passed through to the engine block filters and set off the "water in fuel" alarm.

 

[C lectric]

My understanding is that water CAN get past a normal filter element.

There are Water Blocking Filters that will prevent water getting past the element but that means blocking the fuel flow also.

 

[Portage_Bay]

To be clear. My experience with water getting past the filter elements was with Racor.

I'm aware of what Parker says but there was water in the engine block mounted filters. The engines were still running at cruise RPM when I got the water in fuel alarm and error msg.