Fuel leaking from drain tube

[garyahouse]

Here's where there's no substitute for all the knowledge you guys have. I found a small wet puddle... maybe 2 inches in diameter... under the bike today when I got out of class (I'm a teacher). Here's how it happened: I was pushing and prying, trying to stuff my laptop into one of the saddlebags when I saw a drip coming out of one of the drain tubes under the engine. I reached down and caught the next drip on my finger. I took a quick sniff. Gasoline. Bike was sitting in the sun, temperature today was about 85 (sorry guys, I know it's only April but it's Florida). Gas tank was feeling like maybe about 100 degrees and was filled to perhaps 1 inch shy of the baffle just below the filler cap. My question: Where was the gas coming from? Is this normal? Anything I need to worry about? Anybody know just what comes out of those drain tubes and why ? There are a bunch of them.

HELP !!!

Gary

darksider #44

 

[phroenips]

Here's where there's no substitute for all the knowledge you guys have. I found a small wet puddle... maybe 2 inches in diameter... under the bike today when I got out of class (I'm a teacher). Here's how it happened: I was pushing and prying, trying to stuff my laptop into one of the saddlebags when I saw a drip coming out of one of the drain tubes under the engine. I reached down and caught the next drip on my finger. I took a quick sniff. Gasoline. Bike was sitting in the sun, temperature today was about 85 (sorry guys, I know it's only April but it's Florida). Gas tank was feeling like maybe about 100 degrees and was filled to perhaps 1 inch shy of the baffle just below the filler cap. My question: Where was the gas coming from? Is this normal? Anything I need to worry about? Anybody know just what comes out of those drain tubes and why ? There are a bunch of them.

HELP !!!

Gary

darksider #44

You say the tank was full. It was probably the fuel expanding in the warm tank and coming out of the fuel overflow tube as designed.

 

[TomInPA]

The solution to this problem is to buy a California Emissions bike. It includes a carbon canister to capture evaporative and free gasoline and release it back to the injection system.

Other than that, what Free-nips said. Sheesh, what a name.

 

[wfooshee]

Agreed. Probably fuel expansion or evaporation in the heat. If it does it with half a tank then you've got issues.

OTOH, have you had venting problems? Does your filler cap hiss when you open it? If so, then you've got a pressure build-up in the tank because it's not venting properly.

 

[SkooterG]

Well, duhhh. Let's see - what is it about a 'drain tube' that you don't understand? I hope you bring a better understanding of concepts to your whole 'car tire' thing.

Sorry. I couldn't resist.

 

[SkooterG]

You say the tank was full. It was probably the fuel expanding in the warm tank and coming out of the fuel overflow tube as designed.

Actually, it was fuel coming out of the 'vent' tube. With the cap closed, fuel shouldn't be getting to the 'overflow' tube under *normal* conditions.

 

[SkooterG]

OTOH, have you had venting problems? Does your filler cap hiss when you open it? If so, then you've got a pressure build-up in the tank because it's not venting properly.

If it was a case of pressure build-up, there would not be any fuel coming out of any of the tubes as it would all be in the fuel tank under pressure. And not venting.

Normal operating system. Move along folks, nothing to see here.

 

[garyahouse]

I forgot to mention one thing. I opened the gas tank at that same time. That's how I knew exactly how much was in the tank. Once I did, dripping stopped. Looks like I've got nothing to worry about. By the way Skoot, I enjoyed post number 5. Now I know how my students feel when I ask them, what part of ___ ___ ___ don't you understand? Since you've got the nomenclature down, why aren't you standing in front of a classroom every day? You've got the tools, dude!!!!!!

Looks like if I crash and burn one of these days, it'll have to be caused by Exalto rather than Texaco.

But at least now I know that I've got both a vent tube and a drain tube for fuel vapors and/or overflow... coming out under the bike in that bundle of hoses-- if I understood you all correctly.

Time to load up the Feej and head for the land of learning. It's after 6 already.

Gary

darksider #44

 

[wheatonFJR]

Should I be worried that my FJR isn't leaving puddles of gas under the bike? If dripping is normal, is my FJR normal? Skooty??

 

[RadioHowie]

Well, duhhh. Let's see - what is it about a 'drain tube' that you don't understand? I hope you bring a better understanding of concepts to your whole 'car tire' thing.

Sorry. I couldn't resist.

You say the tank was full. It was probably the fuel expanding in the warm tank and coming out of the fuel overflow tube as designed.

Actually, it was fuel coming out of the 'vent' tube. With the cap closed, fuel shouldn't be getting to the 'overflow' tube under *normal* conditions.

OTOH, have you had venting problems? Does your filler cap hiss when you open it? If so, then you've got a pressure build-up in the tank because it's not venting properly.

If it was a case of pressure build-up, there would not be any fuel coming out of any of the tubes as it would all be in the fuel tank under pressure. And not venting.

Normal operating system. Move along folks, nothing to see here.

Christ, what a grumpy old bastard!

 

[SkooterG]

Christ, what a grumpy old bastard!

That's grumpy YOUNG bastard to you, ya old phart!

:****:

 

[101stpathfinder]

Here's where there's no substitute for all the knowledge you guys have. I found a small wet puddle... maybe 2 inches in diameter... under the bike today when I got out of class (I'm a teacher). Gary

darksider #44

There may have been nothing to learn here, but the entertainment value was worth it.

BUTT now I have to watch my spelling on this forum.... :lol:

 

[garyahouse]

Here's where there's no substitute for all the knowledge you guys have. I found a small wet puddle... maybe 2 inches in diameter... under the bike today when I got out of class (I'm a teacher). Gary

darksider #44

There may have been nothing to learn here, but the entertainment value was worth it.

BUTT now I have to watch my spelling on this forum.... :lol:

Sounds to me like somebody thinks he's funny today. I'll be writing you a pass to the office, and you can tell them that I'll be sending down a referral with another forum member. Now there's two things I expect from you, my mouthy young friend. First you need to apologize to your classmates for the poor example you've set today with that attitude of yours, and second, I want you to write the word "but" 100 times for me on your next post. It will be due when you return to class tomorrow.
You are dismissed.

And remember, if this happens again, you'll be parking that FJR for a month, young man.

Gary

darksider #44

 

[RadioHowie]

I want you to write the word "but" 100 times for me on your next post. It will be due when you return to class tomorrow.

You are dismissed.

And remember, if this happens again, you'll be parking that FJR for a month, young man.

Gary

darksider #44

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Just hedging my bets.

 

[Fred W]

There are two "drain" tubes on the left, underside of the FJR.

One is the "overflow" tube which comes from the well area surrounding the filler neck. The only way that you should see fuel there is if you overfill it (duh!) or if the gasket around your gas cap is leaking.

The other tube comes from the tank vent. This is probably the one that was dripping on yours. The path for venting is through the gas cap itself and into the orange grommet thingee that you see when you open the cap. Inside the gas cap is a check valve and a "restriction" device. When you are driving and using fuel the tank develops a slight vacuum and the check valve opens allowing air to relieve that vacuum. If this vent doesn't work your tank eventually gets sucked in and implodes. This has happened.

When the fuel warms in the tank in the hot sun it expands (are you a science teacher?) and the tank pressurizes. The check valve is closed, so the expanding fuel pressurizes the air and fuel vapors above the fuel. The only path out is through what I called the "restriction device". It looks like a little filter thingee, and it causes a positive pressure to develop before it will allow venting. Some folks theorize that this and the check valve are there to prevent fuel from venting in the case of the inevitable drop.

I have disassembled and modified my fuel cap to remove the check valve, essentially allowing my tank to vent freely. Yes, I am undoubtedly destroying the atmosphere with ventilating hydrocarbons, and am running serious risk of inflammation. I've been told that I will die a fiery death in the event that I dump the bike and cannot extricate myself from under the dripping fuel vent line. But my tank will not implode on itself and will also never geyser up into my face when I open the gas cap at a fuel stop (as some 1st gens are wont to do).

I documented the innards of the fuel cap here: Click for fuel cap pleasure

Sorry, back to your case of the drip. When you have recently filled the bike (with cold gas) and you will be parking it in the sun, you may consider parking the bike on the center stand as a means to keep liquid fuel as far from the cap vent as possible. Or just expect a drip now and then.

 

[BkrK12]

Content self edited.

 

[Big Sky]

Here's what I do when I find a puddle underneath the FJR: I roll up a newspaper, smack it about the fairing several times while shouting, "Bad Motorcycle! Bad Motorcycle!" Someone suggested rubbing the Feej headlight nacelle in the puddle, but that's just mean.

 

[SkooterG]

There are two "drain" tubes on the left, underside of the FJR.

One is the "overflow" tube which comes from the well area surrounding the filler neck. The only way that you should see fuel there is if you overfill it (duh!) or if the gasket around your gas cap is leaking.

The other tube comes from the tank vent. This is probably the one that was dripping on yours. The path for venting is through the gas cap itself and into the orange grommet thingee that you see when you open the cap. Inside the gas cap is a check valve and a "restriction" device. When you are driving and using fuel the tank develops a slight vacuum and the check valve opens allowing air to relieve that vacuum. If this vent doesn't work your tank eventually gets sucked in and implodes. This has happened.

When the fuel warms in the tank in the hot sun it expands (are you a science teacher?) and the tank pressurizes. The check valve is closed, so the expanding fuel pressurizes the air and fuel vapors above the fuel. The only path out is through what I called the "restriction device". It looks like a little filter thingee, and it causes a positive pressure to develop before it will allow venting. Some folks theorize that this and the check valve are there to prevent fuel from venting in the case of the inevitable drop.

I have disassembled and modified my fuel cap to remove the check valve, essentially allowing my tank to vent freely. Yes, I am undoubtedly destroying the atmosphere with ventilating hydrocarbons, and am running serious risk of inflammation. I've been told that I will die a fiery death in the event that I dump the bike and cannot extricate myself from under the dripping fuel vent line. But my tank will not implode on itself and will also never geyser up into my face when I open the gas cap at a fuel stop (as some 1st gens are wont to do).

I documented the innards of the fuel cap here: Click for fuel cap pleasure

Sorry, back to your case of the drip. When you have recently filled the bike (with cold gas) and you will be parking it in the sun, you may consider parking the bike on the center stand as a means to keep liquid fuel as far from the cap vent as possible. Or just expect a drip now and then.

Wordy New England bastard, ain't ya? All that to say what was already simply said?

Actually, it was fuel coming out of the 'vent' tube. With the cap closed, fuel shouldn't be getting to the 'overflow' tube under *normal* conditions.

I want to know how you wipe your ass after taking a RadioHowie. Is it a simple procedure? Or a convoluted, step by step, highly detailed excercise?

Oh yeah,

:****:

 

[Fred W]

Yeah, yeah... Go immolate yersef!

:****: