please help, gas leak

[crich034]

Hey guys I'm new here and I ride a 2007 fz6 and I have a gas leak I cannot figure out. I'm 100% sure it's a gas leak and it is coming from the hose connected to the bottom left side of the tank. The leak happens when I fill up and I'm very careful not to overfill and it continues to happen until there is only half a tank left. The hose is in good condition and I'm at a complete loss for a solution. Someone please help me out so I can put more than half a tank in my bike. You will be my hero if you can help me find the solution. Thanks in advance.

 

[summerb37]

Is the leak coming from the fuel pump itself and/or is it no longer seal correctly to the tank? This would be my guess if the leak is coming from underneath the tank in this location and the fuel hose is not leaking.

 

[crich034]

The leak is coming directly from what I think it's the overflow hose. I have checked the bottom of the tank and there is no leak from there or the fuel pump. There is just a constant light stream coming from that small house connected to the bottom of the tank and hangs near the rear break pedal.

 

[Tahlen]

I had a very similar issue that was caused by the gas tank getting hot in direct sunlight during the day. Yours sounds different though given that you describe it as a light stream and that it leaks consistently down to half.

What I had originally thought was that the metal piping that connects the breather and overflow lines from the top of the tank through to the bottom might have rusted through. This sounds more appropriate for you since it seems like a constant flow until a certain fluid level. Make sure it isn't heat related anyway imo by parking in the shade for a day first.

Link to my thread, photo of the metal plumbing inside the tank that may be your issue. There were other threads about the corrosion issue.

http://www.600riders.com/forum/gara...w-fuel-leak-out-breather-hose.html#post590001

 

[agf]

one is a breather hose so it may be that if the bike is in the sun, its expansion of gas in the tank and then condensation back in the tube.
be interesting to see how much you collect from a full tank if the bike is in the sun. It might be less than you summize.

The other pipe is the overflow and if like me, you like to fill half an inch over the little nozzzle splash guard plate in the tank filler neck, sometimes you'll get petrol all over you foot if your standing on the rh side

 

[crich034]

My bike is kept in the garage so it's not a heat problem. I have been collecting the fuel coming from the line in a jug and it's nearly a gallon. I have also checked the metal connector to the hose and it's also in good condition. Any ideas? I'm hoping to prevent having to take it to a shop to get diagnosed.

 

[agf]

My only other thought is that somehow its siphoning out, not that this is helpful, solution wise. and doesn't really make sense if you open the tank, as all pressure is equalized. I think maybe the corroded pipe possibility is the issue by the sound of the symptoms
I'm sorry I can't be more help

 

[Motogiro]

When you close the filler cap there is a gasket that must seal on the lip of the filler hole. It sounds like when you fill up that gasket is not sealing and the gas gets passed the lip to the outside where the overflow tube allows it to drain out. That cap should feel loaded when you open it or close it. Inspect that gasket carefully!

Also, I believe that tube runs through the interior of the tank and it may compromised. [MENTION=15974]FinalImpact[/MENTION] , [MENTION=6338]TownsendsFJR1300[/MENTION]

 

[FinalImpact]

It sure sounds like its rusted inside. Short of pulling it apart (taking the pump out for a better look), you could use a large syringe as a controlled air source (no lip service), and connect one end to a hose and the other end will need to be plugged for a minute. The goal here is to be able to pressurize the line and not have it leak!

One drains water from the caps brim (harder to plug) the other connects right to the cap. Plug it w your finger and verify it builds pressure... Open cap.

Although we've seen many tanks rusted on the inside, if either hose vents were kinked i know they'll hold moister and they could rust through into the tank... Its possible. You said it leaks from the left side of the tank. I think thats the brim drain. You might have to remove the filler cap assembly to plug that. Let us know what you find.

Take a look at the pictures in this thread. http://www.600riders.com/forum/showpost.php?p=579362

Inside the tank.

 

[TownsendsFJR1300]

With the bike on the side stand and the gas cap open, you can see the drain on the left side(looking down from the top), that is the drain should you over fill(you can see the holes thru the cap assembly. The rear, with the red seal is the vent.

The pic Randy posted is my spare tank with the pump out showing each of those lines

Agreed, it sounds like one of those tubes are leaking which is very unusual (unless you have a bunch of rust inside to start with).


**What you may try doing is fill the tank to the top.
Remove the gas cap, (3 bolts outside, one under the open cap).

Then, put some air pressure ONE at a time, at the bottom of the drain hoses, maybe 5-10 PSI, while holding a finger over the appropriate hole(pressurizing the steel line) at the top.

IF, one of those internal lines are leaking, you'll get all kinds of air bubbles coming up to fuel cap opening. You shouldn't get anything.

(With loosing approx a gallon, that leak is towards the very top, a gallons worth of fuel obviously)

If you do, it time to pull the tank, pump and inspect. If the inside is in good shape and there is a hole in one of the lines, to save it, you may be able to save it with a split fuel line hose and a hose clamp around it or some fuel resistant epoxy. If the fumes can be removed fully, depending on where the leak is, brazing the hole, (sounds small from what your posting and about in the middle of one of those lines) is possible.

BTW, both those lines, at the bottom, have a white stripe of paint on the bottom. They should exit on the right side near the O2 sensor. There's an actual plastic round piece the hoses go thru to keep from flopping around.
As Randy posted, they shouldn't be kinked (it'd screw up the test too). You can easily, follow both rubber hoses down from the tank (bike fully assembled) (I touch mine with a finger and tug feeling the line so I know I'm on the correct line) and gently tug on the lower end of the hoses. The left side hose should track off from the left to the right side and go into that plastic retainer.

For the S1 bikes, the radiator overflow line comes out thru there as well (3 lines). Your should see two if the lines are routed correctly.


Just a larger, easier pic to see:


In this pic, you can see the two lines(holes for venting/draining and 4 bolt holes for the cap. Again, one bolt is UNDER the open cap. The six bolts showing on the outside, 3 work, 3 are just for looks..

 

[FinalImpact]

** Nothing personal here ** but I STRONGLY DISAGREE with the USE of an air source having any more potential than a Turkey baster or a syringe! The reason is this!

Should you pressurize the tank due to a leak; fuel below the leak area has the potential to come right back out and NOT STOP UNTIL THE PRESSURE HAS EQUALIZED!!!​

If nothing else it may even create a formidable vapor cloud of GASOLINE! This is HIGHLY EXPLOSIVE!!! USE EXTREME CAUTION!!!!

Obviously the safest thing to do is to remove all the fuel before proceeding. Use your best judgment on how to remove the remaining fuel but its seems as though riding it "PLACES YOU AT RISK!" Thus, I would NOT ride it off if it were mine.

 

[Motogiro]

Reading post #6, I don't think there's much doubt the line is compromised inside the tank. A gallon of fuel!

 

[TownsendsFJR1300]

** Nothing personal here ** but I STRONGLY DISAGREE with the USE of an air source having any more potential than a Turkey baster or a syringe! The reason is this!

Should you pressurize the tank due to a leak; fuel below the leak area has the potential to come right back out and NOT STOP UNTIL THE PRESSURE HAS EQUALIZED!!!​

If nothing else it may even create a formidable vapor cloud of GASOLINE! This is HIGHLY EXPLOSIVE!!! USE EXTREME CAUTION!!!!

Obviously the safest thing to do is to remove all the fuel before proceeding. Use your best judgment on how to remove the remaining fuel but its seems as though riding it "PLACES YOU AT RISK!" Thus, I would NOT ride it off if it were mine.

Nothing personal taken..

However, your NOT pressurizing the tank..

As noted, the entire fuel cap assembly is OFF THE BIKE. Your putting slight pressure in each of those internal steel lines with your finger over the end of the line controlling the pressure inside that line. The internal tank is NOT pressurized, the main cap is off/open. We are trying to slightly pressurize the line and see if it leaks/ bubbles...

Can bubbles push some liquid fuel up, sure if topped to the very edge, although its leaking about a gallon down so it does NOT have to be filled to the lip.

Short of fumes rolling out and making it to your air compressor kicking on, yes it would be BEST to air up the compressor and turn it off.

Anytime you work with fuel, its a given, it should be in a very well vented area without any ignition sources..

One of those tubes will easily bubble air with some pressure if leaking (a turkey baster may do it as well) but the amount of fumes coming out would depend on how big the hole and the # of PSI applied (again 5-10PSI is plenty)

We're just trying to confirm one of those steel lines is leaking inside the tank.

Similar method as a slow leak in a tube; fill it with air, stick it in a tub of water then look for bubbles...

 

[TownsendsFJR1300]

Reading post #6, I don't think there's much doubt the line is compromised inside the tank. A gallon of fuel!

Actually Cliff, if the Op just separates and finds which line is actually leaking, he can follow it up under the tank and see if it's the vent or overflow..

Then start pulling apart or saving for a new tank..

As noted previously, if that rusted out, the rest of the inside is probably really bad (rust).

And unfortunatly, even if you cleaned the inside of the tank and sealed it, you still have that internal steel line leaking..(short of fixing that, if its worth it)

 

[TownsendsFJR1300]

Had a duh moment...

If the rest of the tank is ok and not rusted up an easy fix;

Remove tank and pump obviously.

Cut out the steel line (rotating pipe cutter) that's failed, 2-3"s (or however long).

Get some new FUEL line ID the same as the OD of the steel line.

Slip it over whats now missing and hose clamp it on both ends! Of course make sure its over a nice clean section of that steel tube... :thumbup:

 

[FinalImpact]

Actually Cliff, if the Op just separates and finds which line is actually leaking, he can follow it up under the tank and see if it's the vent or overflow..

Then start pulling apart or saving for a new tank..

As noted previously, if that rusted out, the rest of the inside is probably really bad (rust).

And unfortunatly, even if you cleaned the inside of the tank and sealed it, you still have that internal steel line leaking..(short of fixing that, if its worth it)

FWIW: The first time I lifted the tank on my "new to me 08", someone had lowered the tank Pinching Both Vent lines! This did not effect driveability. It did allow moisture and fuel to condense in those lines and when straightened, both dumped a mixture of fuel and water!!

That said, there is ZERO rust inside my tank but those steel lines "through the tank" are suspect of rusting through from the inside to the exposed area in the tank. So, I can see a "rust free tank" having this issue due to failure to straighten these lines.​

HENCE THIS POST on 201-03-24 after buying the bike! http://www.600riders.com/forum/how-to-s-/36794-fuel-tank-dont-kink-hoses-w-pics.html?highlight=kink

Upon lifting the tank on a new to me 08 FZ I found both of the breather tubes from under the tank to be completely kinked and restricting air movement.

Don't let this happen to you!

As begin to drop the tank down, reach though the frame rails and pull the tubes back on both sides so the tubes don't bunch up under the tank and get kinks in them!

Reach in here; Pull vent tubes towards the rear as shown!
They should be visible though the opening or they may be kinked under the tank!

DON'T let this Happen!

That's it! Pay attention to details!

 

[TownsendsFJR1300]

Any updates????

 

[Motogiro]

[MENTION=15974]FinalImpact[/MENTION]. [MENTION=6338]TownsendsFJR1300[/MENTION].

I was thinking that if it's just an overflow, you could put a plug at that outlet at the bottom of the tank and ride. It's still important to investigate why there is a failure and possibly other internals that have been compromised...

Sent from Moto's Motorola

 

[TownsendsFJR1300]

[MENTION=15974]FinalImpact[/MENTION]. [MENTION=6338]TownsendsFJR1300[/MENTION].

I was thinking that if it's just an overflow, you could put a plug at that outlet at the bottom of the tank and ride. It's still important to investigate why there is a failure and possibly other internals that have been compromised...

Yep, I thought the same thing.

The only downside is IF you overfill, fuel won't run down into that "little gutter" and out the tube to the ground, but down the side of the tank /bike...(like the old days!!) But yes, it would work. If a permanent fix, cap it at the base of the tank with a hose clamp..

The lil hole I believe at the 9:30 position;

 

[FinalImpact]

[MENTION=15974]FinalImpact[/MENTION]. [MENTION=6338]TownsendsFJR1300[/MENTION].

I was thinking that if it's just an overflow, you could put a plug at that outlet at the bottom of the tank and ride. It's still important to investigate why there is a failure and possibly other internals that have been compromised...

Sent from Moto's Motorola

This type of failure is a serious safety hazard. There is not good outcome without either a proper repair restoring it to proper function or terminating both ends.

Example: IF this is the over fill drain and the BOTTOM IS CAPPED; in the sun its going to push fluid & VAPOR out the top as its now acting as vent. THIS WOULD BE VERY DANGEROUS IMO!!!!

If its the TANKS VENT and it its capped at the bottom it would prevent venting in the heat and could impair operation on sustained runs as it needs to allow air in as the fuel level drops.

I'd pull the tank and pump and inspect it. Find the leak and depending on the OD of the pipe used, splice in a replacement section using two unions. HOWEVER, before making that second cut it may be possible to bend one section away, slide a longer union in place and bend it back. Tighten the union and call it done until it rusts through elsewhere. If the tank is rust free, a certified welder could well in a new section. Something to consider if a new tank can not be found at an affordable rate.