Fuel delivery head scratcher

CharleyB

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1984 Egg Harbor 41 ft dual Crusader gas engines.

Just bought this boat. Survey went well with good sea trial. First day of ownership was a trip to refuel. Both engines died a few minutes apart in my way there. I assumed I ran out of gas because previous owner put only 20 gallons in each tank, although it is only about 30 minutes to get fuel. I put 75 gallons in each tank. Ran great and got back to the slip. 3 days later, I took her out for about an hour and both engines quit 30 seconds apart. Started that trip with gas gauge reading half full. Now it’s not registering any fuel.
Changed both filters on the port engine and can get fuel to pump from a handheld can from the inline filter to the carb but nothing from either tank. It’s as if the tanks are empty but that can’t be. Any suggestions would of course keep my sanity.
 

alldodge

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1984 Egg Harbor 41 ft dual Crusader gas engines.

Changed both filters on the port engine and can get fuel to pump from a handheld can from the inline filter to the carb but nothing from either tank. It’s as if the tanks are empty but that can’t be. Any suggestions would of course keep my sanity.

Can you explain this a bit more?
Can get fuel to the pump from a handheld?

Can from the inline filter to the carb but nothing from either tank?

Some of these boats have 2 filters and one is down low in the bilge forward of the motor. Have you followed the fuel line back to the tank?
 

CharleyB

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Can you explain this a bit more?
Can get fuel to the pump from a handheld?

Can from the inline filter to the carb but nothing from either tank?

Some of these boats have 2 filters and one is down low in the bilge forward of the motor. Have you followed the fuel line back to the tank?
Yes, I can pump from a handheld, upstream from the now glass inline filter to the carb. I did trace the line back to a separator and changed that filter. While the fuel line was disconnected, I could blow into and draw back on the line leading to the separator then tank, so I don’t feel any obstruction.
 

alldodge

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So you have a outboard primmer bulb on a inboard motor?
If so that's bad news

Have a glass inline filter before the carb, more bad news

You traced back to the separator filter, but tracing the line going from the tank to the separator, there is nothing but fuel line and not another filter?

When you blow air in the fuel line going back to the tank, do you hear any bubbling in the tank?

The fuel line attached to each tank should have either a spring loaded antisiphon valve, or an electrical fuel shut off. If your boat has a eletrical fuel shut off valve, then check the connections.

Do these motors have mechanical fuel pumps or electric?
My guess is mechanical being a 1984
 

CharleyB

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So you have a outboard primmer bulb on a inboard motor?
If so that's bad news

Have a glass inline filter before the carb, more bad news

You traced back to the separator filter, but tracing the line going from the tank to the separator, there is nothing but fuel line and not another filter?

When you blow air in the fuel line going back to the tank, do you hear any bubbling in the tank?

The fuel line attached to each tank should have either a spring loaded antisiphon valve, or an electrical fuel shut off. If your boat has a eletrical fuel shut off valve, then check the connections.

Do these motors have mechanical fuel pumps or electric?
My guess is mechanical being a 1984
No primer bulb. Glass filter I put in to help troubleshoot and because I couldn’t find a replacement for this old girl. I hear something but not sure if it is from the tank or my separator. Mechanical pumps. Someone told me the anti siphon valve can’t be it because the engines were running when they died, and for both to fail at the same time would be the worst luck ever.
I like the idea of an electric shut off; however, I don’t see any and the previous owner said there weren’t any. If they are on the tanks I will have to pull the tanks to get at them. The fuel does run through a gph measuring device. I was told there are no valves in those though.
 

alldodge

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With 2 tanks, and each tank feeding 1 motor, and both engines die within a few seconds of each other this would normally be an electrical problem. You did mention (as I understand) your unable to draw fuel from the tank?

Agree, the odds would be great to have both antisiphon valves go bad at same time. If tanks are not vented well they will draw a vacuum and stop the pumps from pumping. That said it would not explain why both die

The flow meters should not cause stopping of fuel flow (or at least the type I've seen). Collapsed fuel line from E10 gas but then again why both

What is the handheld your talking about?
 

CharleyB

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I opened all tanks to vent. That didn’t make a difference. I used a one gallon gas tank and got that to pump.
 

alldodge

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I opened all tanks to vent. That didn’t make a difference. I used a one gallon gas tank and got that to pump.

Ok it doesn't run on the main tank but does on a gas can

If that is correct then its the valves, collapsed fuel line of tank pickup is clogged, and its on both tanks.
 

CharleyB

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I guess if the first time they both failed was because of low fuel (although the broker swears there should have been enough) then the second time because of 2 blocked pickups. Still hard to believe the timing. Thanks for the help. If anything else comes to mind, I’m listening.
 

alldodge

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Only other thing is to go back to electrical, but you said no fuel at the carb

Can measure voltage at the positive side of the coil to see if it drops out but that has no bearing on the fuel supply

Only other thing is if the fuel tank is empty, as in a leak or someone stole it, but would smell if there was a leak of that size

I replaced my tank on my 94 Formula
 

CharleyB

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Only other thing is to go back to electrical, but you said no fuel at the carb

Can measure voltage at the positive side of the coil to see if it drops out but that has no bearing on the fuel supply

Only other thing is if the fuel tank is empty, as in a leak or someone stole it, but would smell if there was a leak of that size

I replaced my tank on my 94 Formula
I’ll pull the pickups tomorrow and try to stick the tanks if I can visualize the fuel level.

A gas thief definitely crossed my mind. Seems even more unlikely than both engines dying together with the same problem
 

Grub54891

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A lot of inboards have calves to switch from one tank to another. Or use each independent of each other for each motor. Do you have them? And are they turned on correctly?
 

CharleyB

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A lot of inboards have calves to switch from one tank to another. Or use each independent of each other for each motor. Do you have them? And are they turned on correctly?
You are on the money there. Being the new owner, I had to rely on the previous owner for basic set up advice. The 3 tanks each supply it's own motor (the center one for a generator. In the engine room, the valves for the center tank are closed and the other two open. I got to the end of my rope so pulled the pickups off the port and center tanks. I snaked a tape measure into the tanks from there and low and behold, port tank empty and center tank 3/4 full (impossible). Turns out the center tank has 3 pickups, all open at the tank, separate from the engine room. My only explanation is that the center tank siphoned all the fuel from the motor tanks and I was left sucking air to the motors. I just closed the correct valves to stop the siphon. Runs now!!!

ALLDODGE, one follow up question...why are glass inline filters bad?

Thanks for all the help you guys.
 

alldodge

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Glass can break, and even the plastic ones are not USCG approved for inboards
 
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