Please Help! Fuel Problems...

Pdunnie27

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May 20, 2012
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6
I have a 1999 Silverline 1700 LS with a Johnson 85ho on back. So I put about 5 gallons of 50:1 gas/oil in my inboard tank and having problems syphoning up to the motor. Takes forever for the primer bulb to get hard once it does I can start the motor and it runs till the gas in the ball goes empty. Just no constant flow. When I hook the same line up to a my little red gas tank it runs like a champ and keeps flow. Any suggestions?*Thanks all!!!
 

rbh

Fleet Admiral
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Mar 21, 2009
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7,939
Re: Please Help! Fuel Problems...

Does the primer ball collapse?
A few guys have had the same issue here and it could be the rubber of the primer bulb is breaking down and the pump is collapsing it do to the preasure and you may have just a issue with the pickup line/filter which could be partialy plugged all these in combination is a head scratcher.
Pull it apart and clean/inspect.
 

Pdunnie27

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May 20, 2012
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Re: Please Help! Fuel Problems...

Brand new bulb used one time when hooked up to a pressured gas tank. It collapses when I squeeze it but then fills back up. Takes a lot of squeezing to get fuel to come up. I do air flowing into motor when I do squeeze
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,921
Re: Please Help! Fuel Problems...

sounds like a plugged fuel pickup screen in the big tank.

Probably means you have bad stuff in the tank, take a look, clean it out if needed.
 

Pdunnie27

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May 20, 2012
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Re: Please Help! Fuel Problems...

Is that screen located on the inside of the fitting connected to the tank and the hose that runs to the brass fitting thats out side the boat. Or where's it located? Thanks for your help
 

MH Hawker

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Jul 13, 2011
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Re: Please Help! Fuel Problems...

It normaly is on the bottom of the pick up tube inside of the tank, You have to pull it all apart, inspect and clean.
 

Home Cookin'

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May 26, 2009
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Re: Please Help! Fuel Problems...

check you vent, too, but sounds more like a pick-up to me
 

Pdunnie27

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May 20, 2012
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Re: Please Help! Fuel Problems...

Pulled up screen and it was spotless...hooked the line back up to the little pressurized tank couple squeezes and the primer bulb was hard and engine fired right up. Any more ideas?
 

UncleWillie

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Oct 18, 2011
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3,995
Re: Please Help! Fuel Problems...

If I understand it correctly....

The engine can pull gas from a portable tank setting on/above the floor, but not from the Main tank under the floor.
The squeeze bulb can pull fuel from the main tank under the floor but the engine can not.

The Main Tank may/should have an anti-siphon/safety valve on the output that requires an extra pound or two of suction to open.

It sounds like the engine's fuel pump is marginal and need to be repaired/rebuilt.
 

Home Cookin'

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Re: Please Help! Fuel Problems...

Pulled up screen and it was spotless...hooked the line back up to the little pressurized tank couple squeezes and the primer bulb was hard and engine fired right up. Any more ideas?

how did it run off the big tank? How was the bulb on the big tank?

did you pump the bulb while it was out?

By "little pressurized tank" I assume you mean a portable tank--never heard of one being pressurized.

I had the same issue (see the thread in the general outboard forum) and found nothing on the pick-up tube although the Iboat experts and a mechanic and I are convinced that was it, and whatever was stuck on it fell off--but may still be lurking in there.
 

Pdunnie27

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May 20, 2012
Messages
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Re: Please Help! Fuel Problems...

Hey unclewillie the bulb will not pull from the big tank at all. When squeezing I hear little suction and sounds like little air coming from the line hooked to the bulb. Is that normal? When hooked up to the metal red portable tank and the lid is locked in position and bulb is pumped it maintains pressure inside the tank and keeps the flow and engine will run all day. Should I try getting a different bulb to hook up to inboard tank? How do I pass the anti-syphon? Thanks again for all your help. I'm new to this and def learning lots.
 

MH Hawker

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5,516
Re: Please Help! Fuel Problems...

if the bulb wont pull it from the big tank your a long ways from the fuel pump I would suspect a bad fuel line next they have been known to go bad inside especial with ethanol fuels.
 

markheck1

Petty Officer 2nd Class
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Mar 31, 2012
Messages
124
Re: Please Help! Fuel Problems...

If it expands real slow on the big tank I would lean towards plugged line, My moms was a nice wasp nest inside the quick coupler on her boat. cleaned everything out real good and it works like a champ. If on the other hand is expands real fast like there's not much resistance it's probably sucking air somewhere
 

Home Cookin'

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Re: Please Help! Fuel Problems...

Hey unclewillie the bulb will not pull from the big tank at all. When squeezing I hear little suction and sounds like little air coming from the line hooked to the bulb. Is that normal? .


you shouldn't hear air and that could be a connection anywhere along the line. However, I had been hearing an air sound with no adverse effects for 275 hours-it might be air sucking in the vent you hear. Still, I would try to find and eliminate it. Could be the seal at the tank.


"When hooked up to the metal red portable tank and the lid is locked in position and bulb is pumped it maintains pressure inside the tank and keeps the flow and engine will run all day."

Not really. the tank must have a vent our you couldn't get any fuel out. Many tanks are designed so you leave the cap loose while operating. There is no pressure in the tank. The bulb pumps gas out, not air in (is your bulb reversed? The arrow points from the tank to the motor).

"Should I try getting a different bulb to hook up to inboard tank? How do I pass the anti-syphon? Thanks again for all your help. I'm new to this and def learning lots"
Anti-syphon is a ball bearing/spring device usually in the hose barb on the tank. disconnect the hose from the tank, then unscrew the barb. At least on my tank it's two units; they might make a single unit from pick-up to barb.

Can you hook your portable tank's line to the big tank and then to the motor? that would trouble shoot your bulb and boat fuel line.

read the thread I posted above
 

UncleWillie

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Oct 18, 2011
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Re: Please Help! Fuel Problems...

Understand that the Anti-Siphon valve is on the tank is a safety device.
In the event the fuel line were to break or come off the motor, Fuel would siphon down hill and fill the bilge with gasoline. (Very Bad!)
The anti-siphon valve introduces a small restriction that would require the fuel line to get a couple of feet below the tank before fuel would flow.
The engine's fuel pump should have no problem pulling fuel up hill.
The valve is there to save your Bacon! Do not remove it to mask the real problem.

You/we have not even determined if one is present.
A few pictures sure would help in getting some fresh eyes on the problem.

The rubber primer bulb may not have enough strength to pull fuel from the main tank. (Normal.)
I am not an OB guy. I know the primer bulbs are normal on the portable tanks.
Is a primer bulb a typical item on an permanently installed tank?

If there is a leak in the fuel line, you will be pumping air and never get any fuel.
You will also NOT see a fuel leak because the anti-siphon valve is doing it's job.

You either have an engine fuel pump that is weak, or getting fuel out of the tank is the problem.
When you "Pulled the Screen" were you able to blow through the fuel line and all the fittings easily?
 

Pdunnie27

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May 20, 2012
Messages
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Re: Please Help! Fuel Problems...

Thanks for all the responses. Ill try to answer all the questions best to my knowledge. First I don't think any line is plugged. Second I had no intentions of removing safety I just don't think my bulb is creating enough suction to pass it. When I pulled up line I could see through the screen and ran some gas down it and flowed fine. I screwed the fitting as tight as I could to the tank and twisted the hose as tight as I could to the fitting. I'm hopefully going to try to replace the fuel line running from tank to the fitting outside the boat and see if there is absorb leak there. If that don't work I'll try new primer bulb and hose. Any other suggestions? Fuel pump was clean and filter was replaced end of last season.
 

Jlawsen

Master Chief Petty Officer
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Apr 22, 2012
Messages
810
Re: Please Help! Fuel Problems...

Bad anti-siphon valve on the main tank.
 

UncleWillie

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Oct 18, 2011
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3,995
Re: Please Help! Fuel Problems...

...When I pulled up line I could see through the screen and ran some gas down it and flowed fine...

... Fuel pump was clean and filter was replaced end of last season....

Are you saying you could pour gas or blow air easily from the Primer bulb through the pickup screen?
That would eliminate an Anti-Siphon valve altogether.

Last Season and Clean doesn't mean Today and Working.
Most fuel pumps have a rubber diaphragm.
A pin hole in the rubber would kill a lot of your pumping capacity.
 
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