Gas pouring out after sitting for 2 months

[VALKMAN]

After 3 Valkyries and over 180,000 miles I have a strange problem. Bike has been sitting for a couple months, went to start her today and I got gas running out all over the left side. Seems to be running okay except for the gas spilling. went back to check, gas is coming out under the right side too. Petcock is off, will the gas eventually stop pouring out? Any help out there?????
Update, by the way woefully ignorant on any carb checking, never had a problem like this before. The gas has stopped pouring out.

[Ramie]

Where is it leaking from, the fuel lines or intake tubes?  Sometimes the intake tubes o-rings dry out and shrink until fuel is introduced again.  They eventually may swell up again but usually it's not all of them at once.

[rww930]

take all sparkplugs out and hit the start button 3 or 4 times before you lock the engine up.

[98valk]

Where is it leaking from, the fuel lines or intake tubes?  Sometimes the intake tubes o-rings dry out and shrink until fuel is introduced again.  They eventually may swell up again but usually it's not all of them at once.

OEM o-rings are Buna-N aka nitrile material which doesn't shrink and/or dry out if not submerged in fuel and Don't swell up from being contact with fuel.
where do u get your statement from? I suggest u look up the material characteristics of Buna-N o-rings.

[VALKMAN]

Update --->
After sitting for an hour, started her up, no leak. Turned the petcock on, now just a small drip at the back of the left side. Turned petcock off, let sit another three hours. Started her up again, no leak, turned on the petcock, no leak. Let run for 5 minutes no leak. Does this mean what ever was going on is solved? Do not have time at the moment to pull the tank and deep dive this. Will keep checking it every couple days and see what I see. Thanks for all the support and advise!!!!!

[98valk]

Update --->
After sitting for an hour, started her up, no leak. Turned the petcock on, now just a small drip at the back of the left side. Turned petcock off, let sit another three hours. Started her up again, no leak, turned on the petcock, no leak. Let run for 5 minutes no leak. Does this mean what ever was going on is solved? Do not have time at the moment to pull the tank and deep dive this. Will keep checking it every couple days and see what I see. Thanks for all the support and advise!!!!!

do u use seafoam which has pale oil in it?   Buna-N polymers come in various acrylonitrile (ACN) content, ranging from 18% to 50%.  The higher the ACN, the less swell it experiences in oil–the lower the ACN, the more swell it experiences in oil. 
the question is what % did Honda spec their O-rings at.

don't use fuel additives that have oil in them.

[The emperor has no clothes]

Update --->
After sitting for an hour, started her up, no leak. Turned the petcock on, now just a small drip at the back of the left side. Turned petcock off, let sit another three hours. Started her up again, no leak, turned on the petcock, no leak. Let run for 5 minutes no leak. Does this mean what ever was going on is solved? Do not have time at the moment to pull the tank and deep dive this. Will keep checking it every couple days and see what I see. Thanks for all the support and advise!!!!!

If the bike is run regularly, it likely won’t happen again. If the bike sits for any length of time, it will almost certainly leak again. It needs new fuel rail o-rings.

[VALKMAN]

Never used any treatments in the tank, don't ever let it sit as long as I did. I will start her every everyday if I have to, just to keep this from happening. Otherwise when I have time I will dig in deeper.

[98valk]

Never used any treatments in the tank, don't ever let it sit as long as I did. I will start her every everyday if I have to, just to keep this from happening. Otherwise when I have time I will dig in deeper.

fuel does not make oem buna-n o-rings shrink and swell.  most likely the end nuts of the threaded rods that hold the carbs together have loosened up.

Further research indicates buna-n can swell in gasoline including ethanol but only a small amount, with gasoline and ethanol removed it will return to it's original size.  I couldn't find any info indicating that buna-n shrinks from gasoline or ethanol.

[hubcapsc]

Without putting words in their mouths I can say that some
Of our members who have been on fire before think you
Should not ignore this and fix it - probably the orings
That the emperor mentioned…

-Mike

[TTG53#1717]

Crude comes out of the Earth these days with various fracking solvents and other chemicals dissolved in the water from the steam etc. etc. etc.. It creates a whole different set of challenges for the guy running the control board that remembers when crude was crude and charge furnaces didn’t have super heated mystery vapors pushing things backward in pipes against the pumps and coking up multiple tubes that ruin the balance of the furnace passes on the way to the fractionating column.

That has nothing to do with fuel rail o-rings but it seems that folks here like to read things in long conversational posts so it’s my turn to be verbose.

Fuel…What is Fuel these days ?

Formulated Gasoline can have as many as 37 different fractions in one blend. At least that’s the # one of our Blenders mentioned one day while he was calibrating an instrument I had to use.

Depending on your state EPA, your predicted temperature range, elevation, etc. you need to have a correct vapor pressure in your gasoline to properly atomize the droplets and allow proper combustion in various engine states. Cold, warm, hot, idling and balls to the wall.
You can have a heavy gasoline fraction mixed with a light gasoline fraction to get things close but then there are all sorts of anti-knock compounds mixed with aromatics, isomers, alkylates and even Butane fractions. All that happens before the proprietary “Engine Cleaners” like Chevron Techron and whatever Shell puts in their “V Power” mix.

One very possible ingredient, and one that a few years back had your average Joe adding a few ounces to each tank for possible better mileage is ACETONE.

Buna  o-rings are not recommended to be used with Acetone. If your local gasoline formulation has an unusually high Acetone fraction then maybe, over the long term, there could be some adverse effects. Maybe the presence of  Acetone could facilitate an adverse reaction with an aromatic compound in that same blend. There are byproducts of catalytic hydrogenation processes that are downright spooky and as much as we used to try to isolate them from the final “product” tank, some always got through.

“Gasoline” fractions and Diesel are not going to attack Buna. It’s some of the other stuff mixed in to create “ Pump Gas” that may just do that.

Let’s remember that these days there are Alcohol compounds in there too.

I used almost exclusively Chevron with Techron in both my Valk and my FI H-D with no issues.
I worked a crude unit , a Naphtha Hydro-Treater and a Rheniformer. I made gas, diesel and blending stocks. I did not blend commercial products.

When ownership of the refinery changed,  the Chevron stations were starved out and replaced by Shell stations with the V-Power blends. Within 5 weeks my Valk fuel rail o-rings and all the o-rings on the feed line from the tank to the Injection pump on the H-D failed.

If I wasn’t alert that day, I figure the Valk would have flared up and burned at the 1st stop light.

The H-D had no hope of running more than a few seconds.

I put a Red Line kit in the Valk and got a kit for the H-D off Amazon. Both high quality kits.

The OEM fuel rail o-rings looked like 20 year old stuff probably should. Mat finish, not shiny like new.
The H-D o-rings simply disintegrated when I used a pick to remove them.

Modern pump gasoline blends may have the ingredients to damage Buna.

[blackvalk]

My bike sat 1 1/2 years..........Big Problem.
I have gas pouring out on the left bank.
I took the tank off but didn't see anything OBVIOUS.
I'm afraid of starting a fire so I need to take it somewhere SAFE.
I live outside of Salt Lake City, Ut.
If someone has a good mechanic to help me, I'll call him and drop the bike off.
I posted the same subject on the general board.
Now that it's not running, I miss it more than ever.
HELP!
BILL

[rug_burn]

    Our bikes are just about all 20 to 25 years old now, and at that age the original Nitrile, aka Buna-N  or NBR, o -rings and hoses will be just about hard as a rock.   If they get disturbed at all they will leak.    I've had to replace all the o-rings on the fuel rails, the vapor or vent rail,  fuel hoses, petcock diaphragm, intake tube o-rings, the carb-to-intake tube rubber piece and more, sometimes several times.  
    If you take it apart, you might as well do it all  (easy to say, I know.)
 

[98valk]

   Our bikes are just about all 20 to 25 years old now, and at that age the original Nitrile, aka Buna-N  or NBR, o -rings   
 

based on what?  ozone affects them.  they are in a sealed system and not exposed to atmosphere.
where is your data that they dry out with age?

75k miles on a '98. had to tighten nuts twice to stop slow leakage. interesting both times it was the same left side carb bank.

hoses are exposed to ozone and atmosphere, so they can fail.

[Skinhead]

There are 2 things that go through a carburetor, air and fuel.  The air contains ozone and the most common fuel contains ethanol, which attacks rubber components.  Almost always, when Valkyries sit for a prolonged period, even with the fuel drained and carbs emptied, the fuel rails will leak when fresh fuel is finally added.  Also almost always, allowing the fuel to soak in the system will stop the leakage. 

I believe the O rings can and do shrink and swell.  There could also be deposits left behind after the fuel has evaporated, that disturbs the seal at the various joints.  Those deposits may be dissolved by the fresh gas and allow the integrity of the seal to be restored.  Tightening the tie rod nuts may assist this process. 

The second paragraph is mostly theory on my part, but makes as much sense as O rings that don't harden or shrink in gasoline.  We can continue to argue about the cause, but I think it's a moot point.  Ride and maintain them and you won't have problems.  Ride safe all.

[98valk]

https://www.technoad.com/buna-n-nbr/

https://www.marcorubber.com/buna-n-o-rings.htm

as noted below, if anything gasoline with ethanol can cause swelling, and never shrinkage of buna-n.

https://www.marcorubber.com/o-ring-chemical-compatibility-chart.htm#chemId=939   gasoline

https://www.marcorubber.com/o-ring-chemical-compatibility-chart.htm#chemId=778   ethanol

https://www.manuf-rubber.com/news/what-is-the-best-gasket-material-for-gasoline/

[98valk]

could some motorcycles with bad grounding causing oem buna-n rings to fail?

https://www.nes-ips.com/what-causes-o-ring-cracking/

" The best way to prevent O-ring cracking is to keep them away from sources of ozone production. These include UV light, electrical arcing and electromagnetic fields. "

"Nitrile O-rings should be assembled wet, using a grease to protect them from ozone. "

[98valk]

Hmmm, I wonder how many have had more carb o-ring leaks from the left side than the right side due to the alternator generating ozone?

"it’s worth noting that nitrile o-rings and seals should not be stored near electric motors or other ozone-generating equipment."

https://www.manuf-rubber.com/news/a-guide-to-nitrile-o-rings-and-seals/

[Ramie]

Where is it leaking from, the fuel lines or intake tubes?  Sometimes the intake tubes o-rings dry out and shrink until fuel is introduced again.  They eventually may swell up again but usually it's not all of them at once.

OEM o-rings are Buna-N aka nitrile material which doesn't shrink and/or dry out if not submerged in fuel and Don't swell up from being contact with fuel.
where do u get your statement from? I suggest u look up the material characteristics of Buna-N o-rings.

Just relaying what happened to me on a standard I owned for a while.  I did eventually replace the o-rings.

[rug_burn]

[\quote]

based on what?  ozone affects them.  they are in a sealed system and not exposed to atmosphere.
where is your data that they dry out with age?

[/quote]

Have you ever tried to remove a Nitrile o-ring that has been installed a long time, like 20 years or more of use?   They get hard as a rock, and usually they break rather than coming off or out unbroken.   That's just my firsthand experience working on cars, motos, and valves and fluid fittings.  Gas in particular I think is hard on them.   I used to design using them for fittings and valves in aerospace applicagtions, and the short life of them was common knowledge and always a consideration in what material to use.  But NBR is still the recommended material for hydrocarbons like gas and oil.

   They harden with age, exposure to heat, aromatic hydrocarbons  (a common component of gasoline), ozone, and are not weather resistant, this according to the Parker O-Ring Handbook, available online for free download..   Their upper temperature limit is listed as 212F TO 250F, pretty low.

 

[Led]

All I can say, is that mine also have "sealed up" after exposure to fuel.  Knock on wood?

I absolutely DREAD taking the carbs off again......let alone break them all apart to do the job!!

I took the carb bank off once to do a decent "de-smog" and rejet when I first bought Her.  I swore, NEVER again!!  Needless to say......a REAL PITA!!

At my age, I lean towards bikes that have only ONE carburetor!!  TWO at the most!  

ValkMan......I also have a Buell!!  It is a 1996 S1 Lightening!