Boiling /Bubbling fuel

[The Wolf]

I am just back from a trip around Europe which took in the Pyrenees Mountains and some really hot days. Anyway I and another CSC rider had problems with boiling fuel just like boiling a pan of water. When I took off the fuel cap I could see the petrol/gas bubbling away. The temp gauge was about two notches from the top and the fans were kicking in all the time. My trike is a 2007 and my friends is a 2005.
Has anyone else experienced this? We were travelling in a line of 5 and I was at the back, I know the air coming to me was not good and we could not get a decent speed up to cool the engine...
Let me know your thoughts............ThumbUp

 

[dirtdobber]

First thing I would check is the fluid level. If empty it may be just low on coolant. If that is good, check the water pump.
next would be a thermostat. Since the fans are doing their job, it has to be in the cooling system. Gas boiling? That is a new one for me. The tank is plastic. Was the engine running during this time?
I would thing the plastic would get really soft if the fuel is hot enough to boil. I am not aware of gas boiling temperature.

 

[Lucky]

Never heard that one. We have ridden in some really hot weather, but never had that happen. Please keep us posted on what you find. RIDE SAFE

 

[Livin2Ride]

Sorry I can't help you with your problem, I'll leave that to the Goldwing Pros, but this condition is not un-heard of as hundreds if not thousands of CamAm Spyders riders have experienced this on machines that where running prefectly normal.

On the CamAm's the heat is trapped under all that "tupperware" and they have a baffle with some insulation between the engine exhast and the tank, but the heat still goes up and boils the fuel.

 

[The Wolf]

Thanks folks I am still delving into this problem...

 

[DeltaDart]

I am just back from a trip around Europe which took in the Pyrenees Mountains and some really hot days. Anyway I and another CSC rider had problems with boiling fuel just like boiling a pan of water. When I took off the fuel cap I could see the petrol/gas bubbling away. The temp gauge was about two notches from the top and the fans were kicking in all the time. My trike is a 2007 and my friends is a 2005.
Has anyone else experienced this? We were travelling in a line of 5 and I was at the back, I know the air coming to me was not good and we could not get a decent speed up to cool the engine...
Let me know your thoughts............ThumbUp

Jake, what speed were you traveling? Because of the airflow through the radiators GL1800s do not like speeds between 10 and 20 mph. When the fans kick on they are pulling air in the sides and blowing it out the front while the air from forward motion is trying to get through the front and out the sides. The result is very little if any air movement across the radiator cooling fins. This is often called the parade mode and it's been a problem since day one with GL1800s. The only truly effective cure for the high temp is to get moving so more air comes in then the fans are pulling through the radiators.

Hope that helps.

 

[rhino 2]

Sorry I can't help you with your problem, I'll leave that to the Goldwing Pros, but this condition is not un-heard of as hundreds if not thousands of CamAm Spyders riders have experienced this on machines that where running prefectly normal.

.

Yep;; ''I had'' a spyder and that was common, On the spyder's some of the problems were caused by the exhaust pipes running under and against the gas tank...

 

[Bikerbozo]

I'm wondering if what you saw was actual boiling. If you were at high altitude when you took cap off gas, might just be pressure differential pulling air bubbles out of gas. Without actually checking temp, I don't see it boiling. Note that boiling point is lower at high altitudes also.

 

[The Wolf]

Some of your comments are very interesting. The altitude one is good as we were in Andorra when it happened the first time. The second time in Toulouse France. You are also right about not getting enough speed up when riding as the roads we hit were quite packed and slow or no movement in hot weather.

 

[Solidbob]

Could also be the fuel pump going out and pulling air in while pumping, will sure cause little bubbles showing at the fill neck. Have had (2) vehicles ever really boil fuel, first was a TO30 Fergeson Tractor due to carb being attached to the exhaust manifold and the tank located over the engine. The other was a Jensen Interceptor with the 440 Hemi Chrysler engine, it was a great driver on the highway but it hated town and Texas temps.... would boil the fuel totally from the carb bowls sitting at a long light.... had to make me an aluminum deflector to send the heat around the carb.

I'd check the pump, it should not pump all the time, off and on depending on pressure required, if it runs all the time its not making pressure or sending fuel into the canister and then on the ground....

 

[DeltaDart]

OP stated two trikes had same issue. Two pumps bad??????

 

[The Wolf]

Yes you are right...I was concentrating on the answers and forgot about my friends trike doing the same thing............

 

[Trikerbobbilly]

I personally don't have an answer so I googled gasoline boiling point and came up with this statement from a person that works in a lab that test gasoline quality.

" Most gasoline has the boiling range of about 90°F - 430°F . You don't normally see it boil though, it typically just evaporates. However if you were using a gasoline you bought during the winter it is very possible. The gasoline changes by season, (summer and winter). Winter gasoline has a higher vapor pressure and contains much more light material such as butane and iso-butane. If you were using that in warmer weather it would boil very easily". Hope this might shed some light on your problem.

 

[The Wolf]

Thanks for that.. When riding along I pressed the button to check the air temp...This was 92F whilst moving...So quite hot..
The fuel was bought in Spain before we entered Andorra and this was in September this year so no winter fuel...
I appreciate all your findings and find the help great..

 

[Trikerbobbilly]

Thanks for that.. When riding along I pressed the button to check the air temp...This was 92F whilst moving...So quite hot..
The fuel was bought in Spain before we entered Andorra and this was in September this year so no winter fuel...
I appreciate all your findings and find the help great..

Gasoline has a boiling point listed as 35 deg.C to 400 deg.C, the reason for the large spread is because there are several factors that determine the gases boiling point. The three largest factors are the crude oil's origin, the process used to distill the fuel and the additives used in the fuel. What I believe happened to you and your friend is that you bought a tank of gas that was on the lower side of the boiling point scale. If you notice that every time you remove the gas cap on your bike there is a slight release of pressure. There are two main reasons for maintaining pressure on a gas tank. One is to raise the boiling point of the fuel slightly so that even at the lower side of the boiling point scale the fuel will not boil inside the tank, if it did start boiling off while the bike is running this would cause the fuel pump to become vapor locked and the bike would die. The second reason for maintaining a slight pressure in the tank (especially for tanks with fuel pumps mounted inside the tank) is to maintain a slight positive suction head pressure on the fuel pump. I believe what happened to you is that when you removed the fuel cap it released the pressure which allowed the lighter compounds in the warm fuel to boil off, similar to opening a soda pop or beer bottle, the pressure in the bottle maintains the CO2 in liquid suspension, once the bottle is opened and the pressure is released the CO2 begins to boil off and you get the fizz, if the beer or soda is warm it will boil off quick enough to actually boil over where as a cold beer or soda will only fizzle slightly. The fuel boiling is most likely more common than you realize, it's just most riders remove the fuel cap and then turn their attention to the gas pump and don't look inside the tank before putting fuel in. Sorry for the long narrative, hope this helps.

 

[The Wolf]

What a reply.. Thanks very much. Your theory sounds just like it happened. Maybe it will not happen again.... Here's hoping...

 

[SMSgt]

My brother had the same issue on a 98 GL1500. The problem is and was that there is so much alcohol in the fuel and it boils at a lower temp that the gasoline does that it was boiling off while the gasoline stayed in the tank.
It really is boiling fuel. We heard a hissing sound on one of our tired butt breaks so we investigated the problem. Realized that the sound was air escaping from around the gas cap. Took the gas cap off and saw the boiling fuel. My brother in all of his intelligence stuck his finger to see if it was hot and found out in a hurry that when there is boiling liquid there is heat and a lot of it.

So before I tore my scoot up I would first not worry about it and second not worry about it. Just keep your tank full and enjoy the ride.
The tanks are pretty well surrounded so a lot of heat stays around the gas tank.

 

[cscsonny]

Honda had a re-call on this same problem back in the late 80's and early 90's with two fuel injected models,the '85 Limited and the '86 SEi.
I had the '86 and on two trips West to Bad Lands and Yellowstone Park,(both trips at 105+ temps)the fuel boiled and the bike would stop running.First time,by the time we took off enough plastic to try and find the problem (sure was hot on the side of that road but the scenery was beautiful) the fuel cooled down and bike started right up.Both times tank was below 1/2 full.Was hard to keep tank topped off as fuel stops were far apart.
Honda's solution to at least keep running was a replacement fuel line which was re-routed in a completely different location.To stop vapor lock.
Solution for boiling fuel was to keep tank topped off as much as possible when riding in temps above 100*.
I also found that "proping" open the fuel door would allow a lot of engine heat to flow through,while riding in extreme hot conditions.