[Thinwaterfishing]

Hello,

I have a Gheenoe LT 25 with a Yamaha 20hp 4 stoke. I am using a 6 gallon fuel tank, with a 3/8 fuel line. For some reason, when I place the tank on the lower deck, fuel does not push into the line. I have to have the fuel line in a very specific manner so that fuel stays in the line. Not sure why, when I know some people have tanks ran from the bow of the boat.

Any ideas? is the fuel line too thick?

Thank you!

 

[firecat1981]

It's not the size of the line, I use 3/8" on my 20hp with no issues. Sounds like you have an air leak somewhere that's letting the fuel drop out after its primed.

 

[Gervais]

I agree with fire cat. I run a 3/8 line on my 25 even though it specs a smaller line (west marine didn’t have anything else at the time) and mine runs fine with my 14’ of fuel line. Just curious, are you running Yamaha fuel connectors?

 

[Thinwaterfishing]

It's not the size of the line, I use 3/8" on my 20hp with no issues. Sounds like you have an air leak somewhere that's letting the fuel drop out after its primed.

Where do you think this leak may be at?

 

[Thinwaterfishing]

T

I agree with fire cat. I run a 3/8 line on my 25 even though it specs a smaller line (west marine didn’t have anything else at the time) and mine runs fine with my 14’ of fuel line. Just curious, are you running Yamaha fuel connectors?

I have tried two different types of hose’s Both the same size, and they have the same issue. Yes, Yamaha fuel connectors.

 

[albrighty_then]

Is the vent open on your tank

 

[firecat1981]

The primer bulb acts as a sort of check valve when it's working right. If you are losing your prime then that's not a bad place to start. Once you prime how long until until the bulb is soft again?

 

[Thinwaterfishing]

Is the vent open on your tank

I don’t have a vent. I usually have to open it on a hot day to decompress the tank.

 

[Thinwaterfishing]

The primer bulb acts as a sort of check valve when it's working right. If you are losing your prime then that's not a bad place to start. Once you prime how long until until the bulb is soft again?

I haven’t checked but I cannot recall the primer ball going soft when I have the hose in the correct angle “below” the tank.

 

[firecat1981]

The only other thing I can think of is the fuel pick up, the straw that sucks up the fuel inside of the tank, is binding for some reason. Look inside the tank and see if it moves around. It shouldn't.

 

[WhiteDog70810]

If it leaks, it will be at a connection 99% of the time. I’d tighter every hose clamp a bit more.

I also had fuel problems that resulted from a lever action fuel bulb at one time. The weak diaphragm fuel pump couldn’t pull through the resistance of the heavier ball valves. A regular rubber fuel bulb helped.

Is the tank made to be run with that motor? Seems odd that it isn’t vented. My motor will die pretty quickly if I forget to open the vent. I’d definitely run the motor with muffs while the fuel cap is removed to see if that fixed the problem. If it does, just get a new tank.

How old is the fuel line? Did it ever work properly with another motor? Ethanol gums up and softens fuel lines over time.

Is the fuel pump on the motor in decent condition? I don’t know outboards well mechanically, but a fuel pump is usually simple to replace.

Nate

 

[sjrobin]

I don’t have a vent. I usually have to open it on a hot day to decompress the tank.

The fuel tank has to be vented to deliver fuel. The vent has to be open when operating the engine. You can close it in the garage if you want.

 

[firecat1981]

I don’t have a vent. I usually have to open it on a hot day to decompress the tank.

You have the new style crap automotive cap. It won't let any fumes out, but allows air in when you draw a fuel into the tank. No way to vent to the atmosphere without taking the cap off. Your tank might have swelled so much that the fuel pickup is out of place, check it.

 

[DuckNut]

I haven’t checked but I cannot recall the primer ball going soft when I have the hose in the correct angle “below” the tank.

That right there says it all. It is an air leak. Start at the fitting at the tank. The little orings on the nipple go bad. If you dont have them look at every fitting and re-examine each one.

 

[Smackdaddy53]

I’ve gotten where if I find an issue with wiring or fuel I’ll replace the whole damn thing and be done because of one part fails and you fix it the rest will usually be close to the end of their service too. If you replace one piece at a time it will bite you later on while you are on the water or you’ll be chasing gremlins more than fishing.
Just from my experience...

 

[DuckNut]

I’ve gotten where if I find an issue with wiring or fuel I’ll replace the whole damn thing and be done because of one part fails and you fix it the rest will usually be close to the end of their service too. If you replace one piece at a time it will bite you later on while you are on the water or you’ll be chasing gremlins more than fishing.
Just from my experience...

Exactly.

 

[Finsleft258]

That right there says it all. It is an air leak. Start at the fitting at the tank. The little orings on the nipple go bad. If you dont have them look at every fitting and re-examine each one.

I’ve gotten where if I find an issue with wiring or fuel I’ll replace the whole damn thing and be done because of one part fails and you fix it the rest will usually be close to the end of their service too. If you replace one piece at a time it will bite you later on while you are on the water or you’ll be chasing gremlins more than fishing.
Just from my experience...

Both of these are so stupidly accurate it's not worth doing any other trouble shooting.

 

[Gervais]

You have the new style crap automotive cap. It won't let any fumes out, but allows air in when you draw a fuel into the tank. No way to vent to the atmosphere without taking the cap off. Your tank might have swelled so much that the fuel pickup is out of place, check it.

On a side note. I have the new style caps as well on my tanks. They would swell so much I couldn’t get them out from under my front deck where there is a ledge to hold them in place. A solution is; popping the top of the cap off with a screw driver, drilling the smallest hole possible straight through the white plunger that lets air into the tank, then heat up a small finish nail and melt the drilled hole on one side so it looks like a half moon and there is barley enough of a hole to let any air out. This will let the tank vent but fuel is dense enough it will take a minute to deep out if the tank is on its side. This is obviously hypothetical and should never be done since vented fuel is bad and fuel shooting out of the fuel line connector when disconnecting it is a better alternative.