Fuel In Tank "Boiling"

[Latemarch]

On another of the forums a couple of owners have smelled gas after a 70mi ride and on opening the tank have seen it "boiling". One owner that saw this has a brand new RT with only 200mi or so on the machine.

While it's certainly possible to boil gasoline it just seems unlikely that that is what is happening. Is there any way that there could be a vent tube or something to do with the fuel pump that would cause it to bubble air or vapor up thru the gasoline?

I'll admit that I've never opened the tank after a long ride when I could see the fuel as it was always way down there and I was refueling......maybe they all do it

[3tracs]

That doesn't sound good at all!

I haven't noticed any boiling fuel, but I have had the gas smell when ever the Spyder gets hot. Been told by two different dealerships that it's normal as the Spyder will dump more fuel then it can burn to cool the engine. Didn't buy it the first time, but when the second one said the same thing... well, I still think it's weird.

[Raptor]

That doesn't sound good at all!

I haven't noticed any boiling fuel, but I have had the gas smell when ever the Spyder gets hot. Been told by two different dealerships that it's normal as the Spyder will dump more fuel then it can burn to cool the engine. Didn't buy it the first time, but when the second one said the same thing... well, I still think it's weird.

That seems strange to me also, though not completely out of the realm of possibility. There is a lot of technology built into these machines, and I'm sure that the amount isn't much. They wouldn't want to wet down and foul the plugs.

As far as boiling fuel goes, I have never seen that. If I did, I believe I would run for cover!!

[boborgera]

On another of the forums a couple of owners have smelled gas after a 70mi ride and on opening the tank have seen it "boiling". One owner that saw this has a brand new RT with only 200mi or so on the machine.

While it's certainly possible to boil gasoline it just seems unlikely that that is what is happening. Is there any way that there could be a vent tube or something to do with the fuel pump that would cause it to bubble air or vapor up thru the gasoline?

I'll admit that I've never opened the tank after a long ride when I could see the fuel as it was always way down there and I was refueling......maybe they all do it

Is it actually boiling or is it expansion,? Like if you leave a full 5 gal. can of gas out in the summer sun. If thats the case [expansion] sounds like a vent tube is blocked?

[krb1945]

If you are smelling gas after riding... make sure the evap purge tube is extended back to the rear wheel area.

As to the gas boiling in the tank... make sure they installed the heat protective pad on the front of the tank. Ken krb1945

[bone crusher]

Simple question...what can create that much heat in/around the gas tank to create that much heat?

If the gas is under pressure, it can be much above 212 degrees for it to boil. This is a very unlikely scenario.

[NancysToy]

The boiling point of gasoline is highly variable, depending on the brand, the octane, and the additives (such as ethanol). It can vary from 100-400 degrees F. It would be possible for some gasolines to boil in the tank, which would increase vaporization and venting. Mere expansion of the gas in the tank from heat could also cause it to vent more heavily. With the evap canister intact, fumes should be vented to the engine intake at certain points of operation. If I understand it correctly, though, when the engine is off the tank is vented through the canister to the atmosphere. Any fumes not absorbed by the carbon would be vented to the atmosphere.

[Raptor]

Seeing that petroleum boils at 410* F @ atmospheric pressure, I'd think the plastic panels would melt before the fuel boils.......

http://www.engineeringtoolbox.com/bo...ses-d_155.html

An interesting factoid on gasoline and how it is made. since the crude is distilled and broken down by various processes, here is what we get, as a ballpark figure:

The chains from C7H16 through C11H24 are blended together and used for gasoline. All of them vaporize at temperatures below the boiling point of water. That's why if you spill gasoline on the ground it evaporates very quickly.

So Scotty may well have a valid argument here... This is cool stuff actually!

[Pilo]

An interesting factoid on gasoline and how it is made. since the crude is distilled and broken down by various processes, here is what we get, as a ballpark figure:

The chains from C7H16 through C11H24 are blended together and used for gasoline. All of them vaporize at temperatures below the boiling point of water. That's why if you spill gasoline on the ground it evaporates very quickly.

So Scotty may well have a valid argument here... This is cool stuff actually!

One Spyder owner in Spain, concerned about the heat issue around the legs and tank, actually measured gasoline temperature sticking a digital thermometer in the tank, after a city ride,and it was around 140°F...

Saludos, Pilo

[spyryder]

Hmmmmm.....think I'll put some on the stove.

[canam9]

Hmmmmm.....think I'll put some on the stove.

[Lamonster]

From time to time the fuel on my Boss Hoss would boil and soon after I would get vapor lock. I added a small fan under my tank and that solved the problem. It only happened if I was stuck in traffic for an hour at a time. Try pushing a 1200lb motorcycle to the side of the road in that kind of heat.

http://www.mybikeforums.com/forums/s...70&postcount=2

[M2Wild]

Heat from a leaking exaust might spot heat part of the fuel tank area causing it to boil over. It's definitely a possibility.

[BajaRon]

That doesn't sound good at all!

I haven't noticed any boiling fuel, but I have had the gas smell when ever the Spyder gets hot. Been told by two different dealerships that it's normal as the Spyder will dump more fuel then it can burn to cool the engine. Didn't buy it the first time, but when the second one said the same thing... well, I still think it's weird.

You would be amazed at how much BAD information is "Common Knowledge". The number of times something is repeated does not necessarly mean it is true.

[BajaRon]

Seeing that petroleum boils at 410* F @ atmospheric pressure, I'd think the plastic panels would melt before the fuel boils.......

http://www.engineeringtoolbox.com/bo...ses-d_155.html

Though gasoline is a petroleum product it is not petroleum. I'm not even sure what they are referring to in that chart as petroleum could be oil.

The accepted boiling point for gasoline is 100-400 degrees. The reason for the wide range is due to the wide range of products described (and used) as gasoline. The different additives, blends and chemical compounds used can make a big difference.

Somehow I doubt that the average rider will encounter a gasoline that will boil at 100 degrees but it is also unlikely that we are using a fuel that will boil at 400 degrees either.

Plus, if you add high altitude to the mix that will also lower the boiling point.

[lightman02]

I have a Cannondale ATV and they have a big plastic fuel tank above the engine just like the Spyder. I have not had it happen but several guys that were running on a hot day have had the fuel in their tanks boil and got vapor locking as well. I can really see this being a possibility with the Spyder as are fuel tanks are pretty close to the engine and the tanks are also metal that will conduct heat. But there are so many Spyders I don't think its a huuge concern as well as I beileve the system would vent itself properly to prevent any problems as the Spyder is pretty high tech.

[NancysToy]

Vapor lock has become pretty much a thing of the past, with the submerged high pressure fuel pumps that fuel incection systems need. Yes, it can happen, but it is very uncommon and is usually the result of a failing or fail;ed component in the fuel system, like a weak pump or a plumbing leak or blockage.

[Raptor]

Vapor lock has become pretty much a thing of the past, with the submerged high pressure fuel pumps that fuel incection systems need. Yes, it can happen, but it is very uncommon and is usually the result of a failing or fail;ed component in the fuel system, like a weak pump or a plumbing leak or blockage.

If I had to pick a culprit it would be improper venting due to blockage. So far I have not heard of any Spyders going into Vapor lock. Of course, there is that whole Cannisterectomy debate that is still raging! Which of course takes us back to venting.

Lamont, that was an innovative fix you implemented to solve your issue on the Hoss. Just the thought of having to muscle that big old thang around makes me winse! Good thinking, man!

[Jornie1]

In all my calculations concerning this topic.. I had completely forgotten the relationship of.... C7H16 through C11H24 What in the world was I thinking ..?? It's crystal clear now!! Len....

An interesting factoid on gasoline and how it is made. since the crude is distilled and broken down by various processes, here is what we get, as a ballpark figure:

The chains from C7H16 through C11H24 are blended together and used for gasoline. All of them vaporize at temperatures below the boiling point of water. That's why if you spill gasoline on the ground it evaporates very quickly.

So Scotty may well have a valid argument here... This is cool stuff actually!

[Raptor]

In all my calculations concerning this topic.. I had completely forgotten the relationship of.... C7H16 through C11H24 What in the world was I thinking ..?? It's crystal clear now!! Len....

Jornie, how in the world could you forget about molecular chains C7H16 through C11H24 ? I'm shocked and appauled...

[Latemarch]

Vapor lock has become pretty much a thing of the past, with the submerged high pressure fuel pumps that fuel incection systems need. Yes, it can happen, but it is very uncommon and is usually the result of a failing or fail;ed component in the fuel system, like a weak pump or a plumbing leak or blockage.

I was wondering if the fuel in the fuel lines could boil after shut-off. Since the vapor couldn't exit via the injectors it might bubble up from the fuel pump giving the impression that the fuel was boiling in the tank.

On start up the high pressure pump would rapidly fill the fuel lines, i.e. no vapor lock.

[scudrunner]

Jornie, how in the world could you forget about molecular chains C7H16 through C11H24 ? I'm shocked and appauled...

I guess as we get older, we tend to forget the important stuff. Just the other day I realized that I had forgotten the Alamo!

[SNOOPY]

On another of the forums a couple of owners have smelled gas after a 70mi ride and on opening the tank have seen it "boiling". One owner that saw this has a brand new RT with only 200mi or so on the machine.

While it's certainly possible to boil gasoline it just seems unlikely that that is what is happening. Is there any way that there could be a vent tube or something to do with the fuel pump that would cause it to bubble air or vapor up thru the gasoline?

I'll admit that I've never opened the tank after a long ride when I could see the fuel as it was always way down there and I was refueling......maybe they all do it

I see this boiling problem goes way back......


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