How do I run out of gas before the tank is empty?

[Grub54891]

Re: How do I run out of gas before the tank is empty?

Yup go ahead and drill a hole above tge fitting,then unstall one of tgese to fill the hole.

 

[bruceb58]

Re: How do I run out of gas before the tank is empty?

one of those hoses, most likely the one in the sender unit is the return line for un used fuel to go back to the tank.

Boats don't have return fuel lines, at least they aren't supposed to!

That line that is going to the sender looks like a modification added by someone! If that line is going to the water separator filter and that has a short tube on it, that is the culprit.

 

[tank1949]

Re: How do I run out of gas before the tank is empty?

Or alcolhol crap sludge stopping strainer. Been there. I removed mine and poilished fuel and then reinstalled it. Also, make sure lenght of pickup tube goes to bottom of tank, not 3" from bottom.

 

[AshleysRevenge]

Re: How do I run out of gas before the tank is empty?

It's late and dark here now, I will cut the fiberglass tomorrow and go from there.

 

[smokeonthewater]

Re: How do I run out of gas before the tank is empty?

STOP! don't do anything hasty.....DON'T cut a hole... BEND the pickup tube as needed to remove, throw it in the garbage and replace it with a new flexible plastic pickup tube!

Pickup Tube right here on IBOATS/COM

 

[AshleysRevenge]

Re: How do I run out of gas before the tank is empty?

OMG thank you, I really didn't want to cut a hole anyway but didn't think about the whole demo and trash it method.

 

[bruceb58]

Re: How do I run out of gas before the tank is empty?

I would be blocking off that line that goes to the sender. If that's a short pickup, that would cause your issue. If both are pickups, once it got to the shortest one, you would stop getting fuel.

 

[smokeonthewater]

Re: How do I run out of gas before the tank is empty?

I would be blocking off that line that goes to the sender. If that's a short pickup, that would cause your issue. If both are pickups, once it got to the shortest one, you would stop getting fuel.

Yep, get rid of the ball valves and extra hose... plug off the second pickup fitting and put in your new pickup, cut to length to about 1/4" from the bottom of the tank at a slight angle and go boating with confidence

 

[AshleysRevenge]

Re: How do I run out of gas before the tank is empty?

Okay your all really helping and I think the last one or two replies may have nailed it... we'll see.

If the shorter pick up falls short of gas wouldn't that be just like a broken straw... then sucking air and causing this entire problem from the "generator" pick up line? I just bent the pickup line to get it out and found a ton of rust on the filter but nothing wrong with the pickup line.

It would almost seem that when someone decided to run both lines to the engine they created a broken straw effect.

I will replace the main pickup line and delete the auxiliary line and find out what happens.

Thanks again.

 

[UncleWillie]

Re: How do I run out of gas before the tank is empty?

Three theories....
1. The second Fuel line is/was for a Generator.
2. The second Fuel line is/was for Return/Bypass fuel from the fuel rail of a fuel injected engine. ***
3. The second Fuel line is/was for a Kicker OB Motor sharing the main fuel tank.

A fuel pickup on the sender mounting plate is not a standard component. Someone Red-Necked that one.
Before you go tearing everything apart, determine which fuel line is actually used to supply the engine,
and most significantly, what does the second one attach to?

It is a 99% probability that the engine should not be attached to the sender mounted fuel pickup.

-------------------
*** Some Automotive Fuel injection systems return fuel to the Tank. Many Diesel units do.
My 4.3 MPI Engine sends the fuel rail bypass fuel back to the fuel filter for another pass at the injectors.
But it does NOT return it to the fuel tank.

 

[81_chapparel194]

Re: How do I run out of gas before the tank is empty?

Boats don't have return fuel lines, at least they aren't supposed to!

That line that is going to the sender looks like a modification added by someone! If that line is going to the water separator filter and that has a short tube on it, that is the culprit.

ok so if it has a mechanical fuel pump like the ones an automotive fuel pump or electrical for that matter where does the excess fuel go??? the pump will pump twice as much fuel as the engine can use even at WOT... and if it isn't suppose to have one maybe some one used an automotive fuel pump on this engine and modified a return line back to the tank.

 

[ondarvr]

Re: How do I run out of gas before the tank is empty?

You said it goes to the fuel/water separator, if so it's not a return line, it just dead ends there. The last person probably didn't know what to do with it when they removed something else and just put it there because it was easy to do and they didn't know better.

Just pinch it off when you go out again and see what happens. Plus you said the pickup tube was rusty, look for pinholes.

 

[smokeonthewater]

Re: How do I run out of gas before the tank is empty?

the pump only puts out a certain psi and does not pump fuel beyond that

IF someone HAD put on an automotive pump (not ALL of those have a return line) it should be removed immediately as it would not have the safety mechanism in case of ruptured diaphragm...


BUT Since the O/P clearly stated that BOTH pickups connect to hoses that route to the water separator with ball valves on each this is irrelevant. The second fitting is NOT a fuel return line.

 

[smokeonthewater]

Re: How do I run out of gas before the tank is empty?

Okay your all really helping and I think the last one or two replies may have nailed it... we'll see.

If the shorter pick up falls short of gas wouldn't that be just like a broken straw... then sucking air and causing this entire problem from the "generator" pick up line? I just bent the pickup line to get it out and found a ton of rust on the filter but nothing wrong with the pickup line.

It would almost seem that when someone decided to run both lines to the engine they created a broken straw effect.

I will replace the main pickup line and delete the auxiliary line and find out what happens.

Thanks again.

This should solve your issues.... happy boating

 

[roscoe]

Re: How do I run out of gas before the tank is empty?

Hello and thank you all for your past help.



The last time we took the boat out (last season) we ran out of gas (so we thought) if we waited about 15min we could start the boat and run for about 30s. We did this along with drifting until we made it back to the ramp.
David

So, if one of the pickup tubes is too short, and then sucks air, how does letting the boat sit for 15 minutes fix it?

 

[bruceb58]

Re: How do I run out of gas before the tank is empty?

ok so if it has a mechanical fuel pump like the ones an automotive fuel pump or electrical for that matter where does the excess fuel go??? the pump will pump twice as much fuel as the engine can use even at WOT... and if it isn't suppose to have one maybe some one used an automotive fuel pump on this engine and modified a return line back to the tank.

Even in automotive applications, it's not the pump that sends the fuel back. In fact, most pumps are in the tank itself. No marine application has a return line at all. Safety issue.

 

[AshleysRevenge]

Re: How do I run out of gas before the tank is empty?

I don't know about the 15 minute thing, but you sit there in the water so long, you try everything. I can only guess the fumes built up, I just don't know, I'm just glad to have got back to the ramp.

 

[Idlespeedonly]

Re: How do I run out of gas before the tank is empty?

So, if one of the pickup tubes is too short, and then sucks air, how does letting the boat sit for 15 minutes fix it?

My guess is once the fuel settles from sloshing around it is able to pick up enough to fill the carb up. The op said it would run for approximately 30 seconds which is close to what a carb can hold in the bowls.

 

[Scott Danforth]

Re: How do I run out of gas before the tank is empty?

my guess it the PO didnt trust the fuel gauge. would go out on the short pickup, as the motor ran out of fuel, would use the ball valves to switch to the original pickup, then know he/she could return.

sort of like the fuel setup in an AC Cobra. No fuel gauge, two fuel pumps and pickups. run on the primary until the motor stumbles, flip the switch to the secondary and head for fuel.

 

[BigDfromTN]

Re: How do I run out of gas before the tank is empty?

my guess it the PO didnt trust the fuel gauge. would go out on the short pickup, as the motor ran out of fuel, would use the ball valves to switch to the original pickup, then know he/she could return.

sort of like the fuel setup in an AC Cobra. No fuel gauge, two fuel pumps and pickups. run on the primary until the motor stumbles, flip the switch to the secondary and head for fuel.

This is what I was thinking after reading this thread.

To the OP... Take her out and run( along with an extra 5 gallons or so of fuel). Run till it quits. Close the ball valve to the line that goes to the sending unit (due to being added) then see if it will fire up and run out the rest of the fuel. If not open that one and close the other original lines valve and test it. If not add the 5 gallons extra and head for a fuel dock or the ramp.

The original tube may have failed, thus the added line. OR as suggested the added line may have been for a kicker or generator with the shorter tube.

On second thought... This could be done on the trailer with a pump and container to catch the fuel.

Best of luck!