fuel/water separator

N

nimrod

New member
Attempted to take advantage of the beautiful day Sunday in the San Juans. After idling nicely away from the ramp at Washington Park in Anacortes with the first mate at the helm, 'Berta's Boy decided to die as we attempted to throttle up to cruising speed. Restart-same thing. Pump the bulb-nada, bulb won't firm up. No fuel getting to the engine. Both tanks full. Bulb wasn't flat, so venting not a problem. And everything worked fine last time out about 2 months ago.

After limping back to the ramp on the kicker and trailering back home, I tear into the fuel supply system, not too happy about the wasted nice day boating opportunity.

Of course the first thing I do is check with the experts at C-Brats.com. Lots of helpful info.

I checked the bulb - worked fine with the intake hose dipped directly into aux fuel tank.

I checked the fuel lines from the tanks through the selector valve to the fuel/water separator cartridge with "mouth pressure" - all clear.

I checked the fuel intake hoses within the tanks with mouth pressure - connected and clear.

I checked the fuel/water separator cartridge - it was full of nasty looking gunk, and had maybe 1/2 pint of water in it.

So basically everything checked out fine except the fuel/water separator cartridge.

So I have two questions:

1) Is it likely that the cartridge could be clogged enough that the bulb would not draw fuel past it?

2) After replacing the cartridge it took a real long time (seemed like an eternity) to pump fuel to the engine again. It took so long that I began to think I hadn't fixed the problem. Admittedly, the lines were clear and the cartridge was empty, but how long should it take to pump the system full again with the bulb?

I'm looking for assurance that the problem was indeed the cartridge, and not the dreaded stuck anti-siphon valve in the tank or a clogged intake hose that I freed or un-clogged by back pressuring.

Thanks

jd
 
jd, hard to tell from your description but it sure sounds like you fixed it. We're in the process of replacing both filters on the Cat along with the low pressure filter under the engine cowl. If you still have problems, look at your engine filter too. Sometimes, if the Racor type filter fills up, enough water will get into the engine filter to cause it to hamper running. That will not go away with replacing the Racor.

Charlie
 
Hi,
I would carry a complete set of fuel filters with you at all times. I Have a large 10 micron fuel water separator and a smaller fuel filter on the front of the motor. I use the marine version of Stabil and use the drain at the bottom of my fuel rail on a regular basis so no water builds up at the bottom of the fuel rail causing injector problems. Yamaha has a nice little drain hose attached so fuel can be drained into a little cup or whatever. I like to change filters in the spring before running to much. You will be the first to know if you have more junk in your fuel tanks to get rid of. Carry the spare filters at all times and what ever tools,rags, catch basins you need to change them should part of your must haves to go boating. Read up on additives and pick one to use. The are reccommended by most dealers. Good luck.
D.D.
 
A few points,

Some cartridge filters have a valve that shuts off if they get full of water to protect the motor.

If you put on a empty, new filter and the hoses are empty, the fuel primer bulb has to draw enough suction to draw fuel from the tank, past the anti-siphon valve, fill the filter and get to the engine. If the carbs are full, there is nowhere for the air to exit the system to allow the fuel to enter.

If this happens, disconnect the fuel hose at the motor, hold the connector at the motor end open with a small screwdriver, point the arrow on the primer bulb up, towards the sky, and pump. You can also fill the filter cartridge with gas before installing it.

When working with the fuel system, remember that it is a system that starts with the tank, involves the fuel pickup, anti-siphon valve, hoses, filter, selector valve, primer bulb, motor connector, hoses and filter inside the motor cover (if fitted), fuel pump, and carbs.

Depending on the problem, starting at one end, (usually the motor end) and working back to the other end without skipping over any part will reveal the culprit.

Hope this helps,
 
Anti-siphon valve,

To check the valve, disconnect the gas hose at the motor end, hold the connector open (or remove it), and pump with the primer bulb, into a container.

You should be able to hear the rattling or rasping noise as the valve opens when releasing the primer bulb. If you can hear the noise, and get a good flow of gas out of the hose, the anti-siphon valve is most likely OK.

An anti-siphon valve is a check valve, with a check ball inside held closed with a small spring. The suction of the fuel pump opens the valve, but the valve prevents any siphon effect from causing a leak if a fuel hose is leaking. Keeping all fuel hoses higher than the top of the tank will also prevent fuel siphon leaks.
 
Lots of good advice. The anti siphon valve is not usually in the tank, but is in the hose barb at the top of the pickup tube and is very easy to install. Many of the C Dories don't really need an anti siphon valve, so you could just carry a hose barb of the appropiate size.

Ethanol is the bain of our outboards. There are more filter problems since ethanol has been mandated. In critical applications, we have used parallel filter systems, where if one plugs up (or the vacuum goes up) we go to the second filter, and change out the first.

As noted, there will be a secondary filter under the cowl and this may be also a fuel water separator--this needs to be checked regularly.

It is possible that your tanks may need cleaning. Beside Stabil, I use Startron. Also in the Yahama outboards, Ring Free.
 
nimrod":38744l37 said:
So I have two questions:

1) Is it likely that the cartridge could be clogged enough that the bulb would not draw fuel past it?

2) After replacing the cartridge it took a real long time (seemed like an eternity) to pump fuel to the engine again. It took so long that I began to think I hadn't fixed the problem. Admittedly, the lines were clear and the cartridge was empty, but how long should it take to pump the system full again with the bulb?

I'm looking for assurance that the problem was indeed the cartridge, and not the dreaded stuck anti-siphon valve in the tank or a clogged intake hose that I freed or un-clogged by back pressuring.

Thanks

jd
Click to expand...

Hello JD,

When I change the fuel filter/water sep with the boat on the trailer, I usually fill the filter with gasoline prior to screwing in onto its holder. Otherwise, it takes a lot of pumping (or cranking) to refill the new filter.

The other thing to watch for are air leaks in the fuel system. Such as air being entrained into the fuel system where the filter assemble screws on or where the bowl screws onto the filter element. And I'm sure there are other places for air entrainment, but the fuel filter area seems most likely if that's what you most recently worked on. Everything will be "great" at idle but when you increase throttle (and, thus, vacuum), the leaks become a problem. Of course, this problem will NOT be apparent when you are at home running the motor on the hose but rather after you've cast lines from the dock and have more at stake. Yikes!...Good thing you had a kicker...with a separate fuel supply.

/david
 
Well David, thanks for your reply and all the others too. It's amazing the wealth of knowledge available here.

David hit it right on, which I realized too at about 4a.m. this morning. Here's what happened:

When I bought the boat the kicker was plumbed into the main tanks. Having learned about the value of redundancy here. I decided to buy a separate, auxiliary tank dedicated exclusively to the kicker. Having done so, I disconnected the fuel line that originally ran from the fuel/water separator to the kicker. And here's where I screwed up: I DIDN'T REMOVE THAT HOSE AND CAP OFF THE OPEN PORT ON THE FILTER! THE OPEN HOSE END WAS IN THE ENGINE WELL, ZIP TIED TO THE BUNDLE OF OTHER HOSES AND LINES WHERE I COULDN'T SEE IT, SUCKING AIR.

OK. Class is in session at the School of Hard Knocks. Lesson learned.

I'm hoping for another nice day this coming weekend in the San Juans.

jd
 
nimrod":2dwxq3za said:
Well David, thanks for your reply and all the others too. It's amazing the wealth of knowledge available here.

David hit it right on, which I realized too at about 4a.m. this morning. Here's what happened:

When I bought the boat the kicker was plumbed into the main tanks. Having learned about the value of redundancy here. I decided to buy a separate, auxiliary tank dedicated exclusively to the kicker. Having done so, I disconnected the fuel line that originally ran from the fuel/water separator to the kicker. And here's where I screwed up: I DIDN'T REMOVE THAT HOSE AND CAP OFF THE OPEN PORT ON THE FILTER! THE OPEN HOSE END WAS IN THE ENGINE WELL, ZIP TIED TO THE BUNDLE OF OTHER HOSES AND LINES WHERE I COULDN'T SEE IT, SUCKING AIR.

OK. Class is in session at the School of Hard Knocks. Lesson learned.

I'm hoping for another nice day this coming weekend in the San Juans.

jd
Click to expand...

HEllo JD,

Bingo on the air leak!!

What you have described is why there is a shut off valve where the fuel line for my kicker is plumbed into the fuel system. When the main engine is running, I shut off the valve and that eliminates the kicker fuel plumbing as a source of air entrainment. I also have a separate gas tank/hose for the kicker so I can run it off a completely separate fuel source.

/david
 
I have cape cruiser 23 witha f-115 yamaha running great I've taken out the anti siphon valves out the first month I had her and also put in a 10 micron yamaaha filter the big one

my question I just changed the yamy filter 10 micron and I was at a marine store I bought for a back up filter a mallory filter it's little smaller then the yammy filter about 5inches vs 8 inches does size matter and has anyone used the mallory filters they are a lot cheaper to replace ?
 
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