Boiling Gas Questions

[Drazil]

I have decided I would throw this out there to see what others think may have been the cause of my gas boiling in my tank today...
I live in Phoenix,AZ where it is usually hot and I have never had this problem before with my '04. Today at around 4pm and temps around 90 degrees I took my sister for a short ride around the area. We rode about 10 miles to a park and drove thru there slowly (about 10 minutes of putting along). We went a few more miles up the Hwy and drove thru another park (about five minutes of putting along) and got back on the Hwy. I did get into the throttle on the long entrance ramp and got up to about 85 and backed off to merge with the traffic going about 70. A few miles up we exited off on a local street for another 2 miles to yes, another park where we were putting along for maybe two minutes. When we left this park I was driving about 20 mph for allmost a mile to the stoplight. About 15 seconds after sitting at the red light I started to smell gas fumes. I looked around and there were cars around so I mostly shrugged it off being about 2 miles from the house. A mile up the road while sitting at that red light (city driving...) I started to notice the gas fume smell again and looked around to see the same vehicles around... more concern this time. Engine was hot but temp gauge was perfect and I have driven in much worse heat and stop and go situations before without any issues. So I ride the last mile home and pull into the garage and when I shut the bike off I hear the bubbling gas...
Now I have had this happen in a car under extreme conditions(that was different) But this, it's not even hot out yet and yes, I was driving slow but not really for all that long. So I started to think back to what was different from the last ride I did which was about 300 miles with no issues. I only came up with the seat is new for me, I recently put a sargent on and have only ridden a few times (shouldn't be an issue). I did drop the seat position to the lowest setting for this ride so I could get my feet grounded better. Outside of that and being 2-up all is the same.
I did open the cap (slowly) and there was not any pressure or spray. I have about 3/4 tank full and can see the top of the fuel and was able to see a steady stream of bubbles rising up from lower in the tank. I pulled the seat and checked the bottom edge of the tank which was hot to touch but I could keep my hand on it with no discomfort. about 10 minutes or more the tank was still percolating away...
I let things cool off and looked around here at other threads then went out and lifted the tank and checked all the lines. I did not notice any lines damaged or kinked or pinched in any way. I checked what I could see without pulling plastic as I need to ride in the morning. I will keep an eye (or should I say nose) on things tomorrow...
mostly curious to others thoughts about what might be the cause...

[Rob Hephner]

Get your gas at either Chevron or QT.

If you can, get your gas at night or after the heat of the day. (Believe it or not you get less gas during the day here)

You got crap gas, I would bet $100 on it.

[MilesFromNowhere]

Get your gas at either Chevron or QT.

If you can, get your gas at night or after the heat of the day. (Belive it or not you get less gas during the day here)

You got crap gas, I would bet $100 on it.


I promise I checked with Ask Jeeves and Wikipedia first, but it seems their tutorials on "Crap Gas" are being revamped.

Care to enlighten those of us that don't understand your diagnosis and your understanding of the root cause?

[Rob Hephner]

It is the stuff in the gasoline, I am not a chemist I can only tell you based upon experience and testing of engines and particularly boost products in the desert. Basically the lower grade of fuel you purchase the more of the overall product that can boil at a lower temperature

As far as the fuel amount deal, our issue is that fluid meters are affected by gas (vapor) in the line adversely, thus resulting in less gasoline being metered as more. It is a big problem and one that even the State Weights and Measure Department does not have an answer for.

If you try it, it will work.

I am not even going to try and argue the point with anyone who can’t belive it or won’t.

[Lead_Deficiency]

was the lower gas tank hot ?

[STeve1300]

Question to the smarter than me people out there..... (no comments please :) )

Wouldn't it be extremely dangerous to open a gas cap, even slowly, if one suspects boiling gas???

[sherob]

Question to the smarter than me people out there..... (no comments please :) )

Wouldn't it be extremely dangerous to open a gas cap, even slowly, if one suspects boiling gas???

Mo yeah :eek: I think I read a FJR had a geyser when he opened his suspecting boiling gas :eek:

[STeve1300]

Mo yeah :eek: I think I read a FJR had a geyser when he opened his suspecting boiling gas :eek:

Imagine that happening in your garage :eek: :eek: !!!

[BigTom]

Interesting...we have had this question before, and it has never been fully answered to my satisfaction...

I normally buy my gas at a 'Mom and Pop', I just happen to know it is Texaco brand. It does land office business no matter the price because of it's location. Which is to say the gas is fresh, all the time. It never sits around and takes on moisture. Another factor for Yuma is that we aren't governed by the pollution laws that those in Phoenix are, we don't have near the ammount of alcohol in our gas.

I do know that Rob is correct. The temp difference and the delivery difference is a thing that many have tried to address, to no avail. When the weather is warm, I'll get 1 full MPG better fuel milage if I fuel in the early morning. Yes, I do check every tank...

[Purm1300]

Darin,

Have you had your fuel tank raised recently?
If you have, check to see that you didn't crimp any of the hoses running up to the top fuel tank.
A kinked vent hose will gurgle gas in your fuel tank.
Just a thought.

Andy

[sherob]

In Houston, they asked everyone to fillup in the morning or late evening a while back. It was supposed to help keep ozone levels down.

I also know firsthand how some gas stations(Randall's) rips you off at the pump. I had an Expedition with a 26 gallon tank... I was at 1/4 tank and stopped to fillup. I put 26 gallons of gas in the truck :eek: Hmmmmmmm :rolleyes: I know others that have had the same issue with them.

[Skywriter]

I will keep an eye (or should I say nose) on things tomorrow...
mostly curious to others thoughts about what might be the cause...

The correct venting/breathability of the tank as fuel is consumed - has been mentioned as a contributing factor to the bubbling of tank fuel.

I would speculate that you have more of a line-pressure/vent problem {partially blocked?} causing a physical "bubbling" -- than actual boiling of a volatile liquid.

Otherwise when you opened the tank there would likely have been an immediate and recognizable expansion/vaporization that would have been... mmmm... a little dangerous indeed.

Recommend finding/checking the vents/lines that permit the tank to breathe properly.

Just an educated guess/suggestion...

Please pass on any wisdom gleaned from diagnosis/corrective action taken ?!?

[UNTMatt]

In Houston, they asked everyone to fillup in the morning or late evening a while back. It was supposed to help keep ozone levels down.

I also know firsthand how some gas stations(Randall's) rips you off at the pump. I had an Expedition with a 26 gallon tank... I was at 1/4 tank and stopped to fillup. I put 26 gallons of gas in the truck :eek: Hmmmmmmm :rolleyes: I know others that have had the same issue with them.

You can contact the Texas Department of Agriculture-Weights and Measures (http://www.agr.state.tx.us/agr/program_render/0,1987,1848_5615_0_0,00.html?channelId=5615) and report that issue. Those pumps are supposed to be calibrated regurlarly and they are off, fixed. I had that happen, once a long time ago.

Gas boiling temps vary depending on the additives. I'm not so sure that with the influx of ethanol into our fuels that the boiling point hasn't been lowered in our fuels. I'm also not so sure that this is boiling fuel as it is venting in the fuel tank somehow. I rode a 1998 Triumph Daytona that the fuel tank was directly on top of a very hot inline triple and never heard any fuel boil. That bike's gas tank was by far closer to the heat than the ST's tank is. I miss that bike. :(

NOTE: That is my wife on the Daytona...just for those that don't know me.

[UNTMatt]

[I]The correct venting/breathability of the tank as fuel is consumed - has been mentioned as a contributing factor to the bubbling of tank fuel.

I would speculate that you have more of a line-pressure/vent problem {partially blocked?} causing a physical "bubbling" -- than actual boiling of a volatile liquid.

Otherwise when you opened the tank there would likely have been an immediate and recognizable expansion/vaporization that would have been... mmmm... a little dangerous indeed.

Recommend finding/checking the vents/lines that permit the tank to breathe properly.

Just an educated guess/suggestion...

Please pass on any wisdom gleaned from diagnosis/corrective action taken ?!?

I agree.

Mine has 'bubbled' since day one. Personally, I think it's how the ST vents the tank. I've opened the gas tank while it's been bubbling and have not seen anything that looks like the pot of water I cooked my spaghetti in last night.

[turbocity tom]

The ST has a return type fuel system, that is the fuel that is unused by the engine is returned to the tank. With many periods of slow running, the overall temperature of the fuel will increase alot, low engine demand- alot of fuel returned to the tank. Additionally, we may still have fuel at the gas stations that is the "winter" blend which has a lower vaporization point. All of this leading to an possablity of fuel "boiling" in the tank.

Tom

[b.carez]

The venting makes more sense to me than the fuel boiling. Would be interested to here what the problem actually turns out to be.

[STeve Kelly]

Reading these posts made me think about my experience yesterday. I pulled into my garage after a 70 mile run and turned the key off. The bike was hot as the fan was running when I turned it off. I soon noticed a glug-glug sound coming from the tank area. It did this a couple of times.

Way was that? Bike is an '06 ST

[Drazil]

was the lower gas tank hot ?

I actually pulled the seat and checked the surface temp of the upper and lower tanks with my hand. The top tank was hot but I have felt it hotter before and the lower seemed no hotter than expected for the situation of driving. I let the bike sit for about 5 minutes before making the not necessarily best decision (as some have mentioned) to open the tank. I was confident with my decision and methods allthough I realize I should of left the bike in the driveway to cool and vent, but big fan and nice breeze and all is okay.

[Drazil]

Darin,

Have you had your fuel tank raised recently?
If you have, check to see that you didn't crimp any of the hoses running up to the top fuel tank.
A kinked vent hose will gurgle gas in your fuel tank.
Just a thought.

Andy

I have not raised the tank recently, other than after this last night to take a look at such possibilities. That is why I mentioned the sargent seat and looked at the front tab that sets into the front seat adjuster. I do not think that it is possible to pinch off any lines but I am going to take a second look at that. Lowering the seat and it being a bit warmer are the only variables that make sense.
I am not cetain that the gas was actually boiling as many mention, could be a venting issue. The bubbles as I will call them were coming at a very fast and consistent rate, hence the boiling term,which at this point I think I should not rule out yet. I am searching more towards the venting issue being the cause.

[Gonzo]

Pardon my ignorance, but is there an activated charcoal cannister in the system? If so, could it contribute to the problem, especially if the tank has been overfilled and the cannister is soaked?
gonzo

[Drazil]

This am I decided to pull some of the tuperware and check fuel lines, etc. First I will mention that while doing this I found other issues from the last time bike was in shop back in December. I found I am missing both bolts from the right muffler clamp and one of the bolts on the left side was a bit loose. Also a few of the rivets are missing from the lower cowl. I did not find any concerns with the lines and all was hooked up and routed properly. So I rode over to the dealer that did the last work to talk to them about the gas, rivets and bolts. They said yes that they pulled the mufflers and that the bolts must of come loose somehow??? they said they will replace bolts and rivets for no charge... gee, do I feel lucky... About the gas, not a clue. they think I was hearing the cooling or something else so I asked about the little bubbles coming up inside the gas tank... insert blank stare... so I leave and ride around a bit which included getting stuck in traffic jams. After about 20 minutes I thought I was smelling gas again so I pulled into a large parking lot and rolled around a minute looking for a shady spot. There were none so I parked and shut the bike down. As I reached for the key and was checking the coolant temp (which was three bars) I saw my air temp gauge start flashing... Okay... it is Phoenix and yes after that the temp was reading 97 degrees which is about right. I just have not had the air temp top out before, even in traffic... just thought it was out of place.
So, no bubbling but a slight smell. I spend a few minutes in a store and decide to ge the bike home, about 15 miles. While stopped at red lights I would get the gas fumes again but no bubbling this time. When I got home I put the bike on the center stand and fired it up and let it idle for a few minutes about a minute in I started getting the gas fumes again. This is actually a strong smell of gas. Outside of the smell the bike did seem to run normal.
Question would be: maybe with yesterdays bubbling is it possible that gas could of been forced into the evap canister and is now just purging out the vent lines? I checked the vent lines and there is no moisture present...

I am busy the next few days but will check back to see any ideas. probably will test one more time and if same results let the dealer look at things...

Thanx for the input

[dmulk]

Pardon my ignorance, but is there an activated charcoal cannister in the system? If so, could it contribute to the problem, especially if the tank has been overfilled and the cannister is soaked?
gonzo

I'd have to 2nd this. It makes a lot of sense.

Do you top your fuel off? Have you ever "dropped" your ST?


I'd pull the Evap and see if you smell gas / see if it's blocked.


Also, is your bike under warranty still?

<D>

[woodybelle]

I had my gas tank boil. It was over 100 degrees and I had just rode 40 miles home from work. The last 6 miles were at slow speed. I opened the cap when I parked the bike and the tank was pressurized and a geyser of gas sprayed all over the bike. I slammed the cap shut and it sat there and sounded like heavy boiling for at least 15 minutes. Earlier in the day I had run out of gas and had to dump gas into the tank with a can with no spout. Needless to say all of the gas did not go into the tank. It probably got into the vent system and possibly saturated the cannister. The bike smelled lke gas fumes several times for at least a week. I have not had another problem since.