Fuel blockage on seafari

McGillicuddy · #1 11-07-2009, 08:09 PM

I think I have something blocking my fuel flow causing my fuel pump to work harder than it can.

I ran about 50 miles last Sunday and ran flawlessly, but when I got back to the kelp beds I put it in idle and we started drifting to fish. After about a minute of idling, the motor would die.

I know the pump creates about twice as much suction at speed than at idle so to some degree that substantiates the ability to run at speed. Switched over to auxiliary tank to run home and idle was fine - in fact I let it idle for 15 minutes at the dock while fetching the trailer.

I've removed the horizontal brass fitting and it doesn't seem to have a check valve. Wondering about the supply elbow on main tank. If I unscrew that what will I find? Is there an anti-siphon valve within that elbow? Or is there crap in the pickup tube? How would I determine that?

stumpie2 · #2 11-07-2009, 09:08 PM

THERE SHOULD BE AN ANTI-SIPHON VALVE THREADED TO THE ELBOW AND THERE SHOULD ALSO BE A SCREEN ON THE END OF THE PICKUP TUBE. IF ITS NOT ON THE END OF THE TUBE THERE WILL BE A CONE SHAPED SCREEN WHERE THE PICKUP TUBE TREADS ONTO THE ELBOW. DONT FORGET IT MAY ALSO BE A PROBLEM WITH THE VENT TO THAT TANK. JUST MY .02

McGillicuddy · #3 11-07-2009, 10:06 PM

Thanks for the feedback nuthinfancy. I was pretty sure it wasn't the vent cause I usually check it for air release when I'm filling up. I removed the fitting at the elbow and put a light in and then a q-tip to feel for a check valve spring and found none. I then removed the elbow and found a blob of what appears to be silicone:

Based on where I found the blue blob any screens are either deteriorated or absent. My guess is that sealant from the fuel sensor broke off or dissolved over the years due to the ethanol gas and each time I top off the tank the ethanol eats away at the silicone or whatever was used as a sealant. Make sense?

stumpie2 · #4 11-07-2009, 11:13 PM

WELL YOU KNOW THERE ISNT A PROBLEM WITH THE ENGINE OR PLUMBING FROM YOU TANK SELECTOR VALVE CORRECT? IF SO, THE PROBLEM IS ASSOCIATED WITH ONE TANK. THE SILICONE IS PROBABLY CLOGGED IN THE HOSE FROM THE TANK TO THE SELECTOR OR IN THE SELECTOR VALVE NIPPLE. TRY TO BLOW BACK INTO THE TANK THROUGH THE PICKUP TUBE TO BE SURE THERE ISNT ANYMORE "BLUE GOO". OBVIOUSLY IM ASSUMING YOU HAVE TWO BUILT IN TANKS WITH A SELECTOR VALVE AS I DO. ALSO CHECK ALL CONNECTIONS AS YOU MAY BE SUCKING AIR SOMEWHERE. TRASH ALL RUSTED/CORRODED HOSE CLAMPS AND REPLACE WITH STAINLESS. AT LEAST YOU HAVE THE PROBLEM ISOLATED. MAYBE A PIN HOLE IN THE PICKUP TUBE ABOVE THE FUEL LEVEL. JUST THINKING AS I WRITE.

McGillicuddy · #5 11-08-2009, 04:01 AM

Quote:

MAYBE A PIN HOLE IN THE PICKUP TUBE ABOVE THE FUEL LEVEL.

That is an interesting possibility as this has occurred @least twice in the last month as I burned half the projected fuel and the size of the glob is obviously bigger than any logical filtering screen.

How do I get to the pick-up tube, are we talkin' an arthroscopic cam of sorts or wtf?

Clearly there is some flotsam in the tank. Should I just siphon/filter the balance of the tank out, or get a proper fuel polishing service... cost me about 350 clams out here...

Fr. Frank · #6 11-08-2009, 11:17 AM

Your Seafari is a 20' like mine. Pull the fuel tank cover out of the floor, and everything is right there, easy access. Remove the fuel feed hose from the fuel pickup fitting on the tank and then remove the fuel fitting, if yours is not a welded fitting. When you remove the fitting, the pickup tube into the tank comes out with it. You can easily see if there's a problem and make any necessary repairs. If your fitting is welded, remove the hose and gently blow high-pressure air down into the tank to blow out any temporary obstruction. Buy new gaskets for the fuel sender, remove the sender and visually inspect the tank. You can also use the sender opening to siphon out any remaining fuel in the tank to inspect for loose debris. If you find loose debris, there are two ways to remove it. One is the terrycloth shop-towel-on-a-wire method, and slowly and carefully swabbing out the whole tank. The other is to remove the tank and wash it out yourself. You can wash out the tank with water and Dawn dish washing detergent. After doing this twice, then blow a hand-held hair dryer into the tank to dry it completely before re-installing the tank.

This is very important: Install all new fuel supply hoses and filters regardless of whether you're re-installing the fuel tank, or just doing a minor clean-up. Don't re-use any old hoses. Consider replacing the vent and fill lines as well.

I put an inline 30 micron particle filter on mine just 6 inches from the pickup. Then my fuel line goes into a 10 micron water-separating Sierra filter with a water drain on it. From there it goes to the fuel bulb and into another (inside the cowling) inline 30 micron particle filter to catch any degraded hose debris.

You can literally do all of this in about 4 hours. The hardest part is removing the fuel tank if it is needed. Bring a cooler on board, and lots of terry shop towels. Better yet, bring a friend who will work for beer and snacks (or Coca Cola). Having somebody to talk with and complain to while working can be a real help.

McGillicuddy · #7 11-08-2009, 06:18 PM

Thanks for the feedback Fr. Frank.

Quote:

Pull the fuel tank cover out of the floor, and everything is right there, easy access.

Fuel tank cover is off; as it is currently set up, vent line is visible at the fore port side of the tank, and sending unit is visible near middle of tank. Fill tube and fuel supply tubes are side-by-side at the back of the tank, actually under the deck, just fore of the aft hatches.

Quote:

When you remove the fitting, the pickup tube into the tank comes out with it.

The gas pickup(elbow)fitting is pictured above. this was located at the aft end of the tank right next to the fill hose. A pick-up tube did not come up with it when removed. The "pick-up elbow" is brass - the welded female fitting appears to be aluminum, potential problem here? Location-wise does it sound like the fittings are in the right places?

Quote:

Then my fuel line goes into a 10 micron water-separating Sierra filter with a water drain on it.

Does that filter come like that and do you know the part number - I'd love to use the clear bowl system as opposed to my current sierra fuel/water separating filter?

Quote:

I put an inline 30 micron particle filter on mine just 6 inches from the pickup.

If I'm understanding you correctly, your 30 micron particle filter is situated between tank and the fuel/water separator about 6" from the tank fitting?

Fr. Frank · #8 11-09-2009, 12:07 AM

Quote:

Fill tube and fuel supply tubes are side-by-side at the back of the tank, actually under the deck, just fore of the aft hatches.

That's just a bit different from mine. My fill tube is located just in front of the rear deck line, and the pickup is just aft of the deck line.

Quote:

The gas pickup(elbow)fitting is pictured above....A pick-up tube did not come up with it when removed.

That's a problem. Check and see if you have a pickup tube attached to the welded-in fitting on the tank. If your pickup tube is not serviceable, you may have to put up $$ for a new tank

Quote:

Location-wise does it sound like the fittings are in the right places?

Yeah, pretty much. I'd prefer the pickup out from under the rear deck. You might want to consider an access plate for that.

Quote:

Then my fuel line goes into a 10 micron water-separating Sierra filter with a water drain on it.

Does that filter come like that and do you know the part number - I'd love to use the clear bowl system as opposed to my current sierra fuel/water separating filter?

Sierra Aqua View fuel fliter

Quote:

If I'm understanding you correctly, your 30 micron particle filter is situated between tank and the fuel/water separator about 6" from the tank fitting?

That is correct. It is a clear plastic disposable filter with a paper element I purchased at Home Depot, like you see often used on industrial gas engines and lawn-mowers. I use it to catch particulate matter that may get into the tank before it gets to the water separator.

McGillicuddy · #9 11-09-2009, 04:40 PM

Thanks again, Fr. Frank. I did cut a 10" hole in the splash-well for a Beckson water-tight plate which gives me reasonable access. Still, assessing the pickup tube will be an issue. Maybe it's time to pull the tank and have a closer look at things.

How often does that fuel/water filter get changed out, or do you just clean it out? Kinda pricey for a disposable maintenance item...

Fr. Frank · #10 11-09-2009, 05:12 PM

Quote:

How often does that fuel/water filter get changed out, or do you just clean it out? Kinda pricey for a disposable maintenance item...

If you keep draining the water out, the filter will last for years. The purpose is to separate the water from the fuel. This one does that and the water then flows down into the bowl to be emptied. Normal water separators are only discarded because they become full of water, not because they get clogged. They are still capable of filtering the water out of the fuel, but no longer have a place to store that water. This will have the life of 20 disposable cartridges. You only need to change the paper filter element out when it becomes block by debris, or when the outer casing rusts through. With ongoing maintenance, that can be a very long time.