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Discussion Starter · #1 ·
I was out for a ride yesterday. Did one long stretch of 1/2 gear rocky stuff. Stopped for a bit and I could hear the gas bubbling in the tank. Shut the bike off, took the gas cap off and steam was coming out, gas was boiling. I couldn't beleive it. When I took the cap off, it made a bit of a swoosh noise, but not too much. My bike is an 07 SE. It ran fine, didn't notice any performance issues. But it looks like the gas cap is moved forward, getting real close to the ignition switch on my TT bar clamps/dashboard. Strangly though, the tank itself didn't feel that hot? I just don't get it. I guess the gas is under some pressure in the tank and has a much lower boiling point then water. My vent tube isn't plugged, the tank area is clean underneath the cover, I don't have any of the three mods so what gives? Maybe I'll try premium next time around. I'm a little concerned about this as this is friggen dangerous. The gas vapors are coming out of the tube and right near the hot exhaust...since we know the exhaust glows red hot...I might be riding a ticking time bomb!
 

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Quite a few of us have had this problem :thumbsup: Haven't blown up yet, you'll be fine.
 

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Discussion Starter · #3 ·
Has yours done it when riding normal speeds, ie, not 1st/2nd for prolonged periods of time?
 

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It happened to me a few times and even had gas come out the breather hose. I drilled out the vent on my gas cap a little bit and havent had any issues since. Got my new gas cap the other day so we will see if it does it or not. :thumbsup:
 

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Discussion Starter · #6 ·
I'm running 89 octane. Haven't tried 94 yet. It just doesn't make sense.
 

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i had the same issue.i think it was due to my gas cap not venting. took out the ball bearing inside the cap and hasnt happened since. possible winter fuel/or vapor lock?
 

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Discussion Starter · #8 ·
I'll check that out, maybe my vent house and or stock gas cap is not doing it's job. I know for sure the tank isn't hot. I'm not 100% sure of the boiling temp of gas, but it's certainly pressure depended. Since there is some pressure in the tank, it would lower the boiling point. My was really going good, gas steam coming out and all. Not nice. What's going to happen when it's 35C here in the summer? :(

I just talked to my brother in law, he's a chemistry professor in the local university. Anyway, he said that what was happening was the lower flashpoint additives were what was boiling off. Chemicals such as hexene, ethalene, benzeen, glycol etc have a lower boiling point, approx. 60C and boil off first. The actual gas is higher. It's one of these things that's hard to compare from one case to another because gas differs all over the place. Different compositions so, it's hard to say what is in one compared to gas down south from me, 1500kms away. So, the investigation continues. I'll try higher octane to see what happens next time.
 

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if the tank is not venting then the tank will create a vacuum in the tank due to the pump, when the vacuum increases the boiling point temperature lowers and the gas will start boiling. More vacuum = boils at a lower temperature. Check to make sure it is venting properly.
 

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supraman23 said:
i had the same issue.i think it was due to my gas cap not venting. took out the ball bearing inside the cap and hasnt happened since. possible winter fuel/or vapor lock?
Rode today. Heard this same sound I think others are hearing. It sounds very much like it is boiling. When I removed the cap, the vapor pressure escaped, and no more boiling sound. Look inside the tank, and don't see any bubbles. Replace/tighten cap, and almost right away, the boiling sound is heard again. Remove cap, and this time the vapor pressure was less than the first, but still present. Still no bubbles in the gas. Replace/tighten cap again, and sho'nuff---it sounds like it is boiling after a few seconds.

My verdict? The little BB in the gas cap is rattling as vapor escapes past it. I think it is a one-way valve. The rattling sounds very much like it is boiling.

Even though sources claim gas can boil at 100° F, I bet that we aren't experiencing that. Just a gut feel, though.

Boiling Point of Gasoline

Gasoline as used by vehicles is a mixture of roughly 230 different chemicals. Gasoline formulations vary depending upon the location, time of the year, environmental regulations, and availability. If the PEAC user looks up the boiling point of gasoline on the PEAC tool, the temperature 102o F (or 39o C) is displayed. But the information is misleading. Gasoline boils over a range of temperatures, with the most volatile components starting to boil away at roughly 102oF. The less-volatile components will boil at higher temperatures. Gasoline boils over range of temperatures, between 39 and 200o C (102oF and 392o F) typically, the temperature range varies depending upon the formulation. The final boiling point of the last residual of gasoline might be typically 225oC (437oF). This is in contrast to a pure chemical such as heptanes (one of the components of gasoline) which boils at a single temperature (209o F; 98oC).
 

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Discussion Starter · #11 ·
Boiling Point of Gasoline

Gasoline as used by vehicles is a mixture of roughly 230 different chemicals. Gasoline formulations vary depending upon the location, time of the year, environmental regulations, and availability. If the PEAC user looks up the boiling point of gasoline on the PEAC tool, the temperature 102o F (or 39o C) is displayed. But the information is misleading. Gasoline boils over a range of temperatures, with the most volatile components starting to boil away at roughly 102oF. The less-volatile components will boil at higher temperatures. Gasoline boils over range of temperatures, between 39 and 200o C (102oF and 392o F) typically, the temperature range varies depending upon the formulation. The final boiling point of the last residual of gasoline might be typically 225oC (437oF). This is in contrast to a pure chemical such as heptanes (one of the components of gasoline) which boils at a single temperature (209o F; 98oC).


This basically reiterates what I was saying above. In my case, the fuel was definately bubbling and boiling, with or without the cap on. I'm not mistaking this for something else. Steam was coming out for some time. Like the explination above says, it was only some of the additives boiling off, not the entire fuel. Even still, that isn't particularly good either. That stuff is in the fuel for a reason, if you alter the composition by boiling off additives, what are you left with and what can/will it do to the engine? Has anyone brought this up to their dealer? As for modding the fuel cap, that ball is there as a check valve, if you open the vent up completely, for air flow both ways, what does that do to the efi? doesn't the check engine light come on? I know on a car if the cap isn't tightened down properly, you'll get a light.
 

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Only solution thats ever came up to tell if its actually boiling or just bubbling from to much pressure is to


Stick your finger in it and see lol :lol:

Dont think anyone has been brave/stupid enough to try though :lol: :thumbsup:
 

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Discussion Starter · #13 ·
bberck said:
Only solution thats ever came up to tell if its actually boiling or just bubbling from to much pressure is to


Stick your finger in it and see lol :lol:

Dont think anyone has been brave/stupid enough to try though :lol: :thumbsup:
Bubbling/boiling, same thing. The pressure changes the boiling point. The various additives have different boiling points. That is what was bubbling in my tank. The actual tank plastic wasn't really even all that warm. Makes me wonder if maybe it's air or something? But that doesn't make sense either, certainly wouldn't explain why there was steam coming out.
 

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Tiggyboot said:
The actual tank plastic wasn't really even all that warm. Makes me wonder if maybe it's air or something? But that doesn't make sense either, certainly wouldn't explain why there was steam coming out.
Steam was most likely the vaporized additives/hydrocarbons that reached their boiling point.

From what I read (and I just posted that paragraph to add to what you/others were saying) gasoline can start to boil at 100°F, and where I live, the ambient air temp can be 115°F, so a tank sitting on top of a running Raptor engine has got to reach 100°F easily for many of us. For me, it could get to 120°, I'd imagine.
 

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Tiggyboot said:
As for modding the fuel cap, that ball is there as a check valve, if you open the vent up completely, for air flow both ways, what does that do to the efi? doesn't the check engine light come on? I know on a car if the cap isn't tightened down properly, you'll get a light.
You will get a fuel light on the raptor. I had mine running one time so it could warm up in the winter, and I was filling it up and the fuel light was on until a minute or so after I put the cap back on and it went off.
 

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Discussion Starter · #17 ·
Sontag_Slim said:
there are 2 balls in the cap (big one and a small one)...I took out the small one and never had this issue again.....
do you have to take the cap apart or just pry the little ball out?
 

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Tiggyboot said:
Sontag_Slim said:
there are 2 balls in the cap (big one and a small one)...I took out the small one and never had this issue again.....
do you have to take the cap apart or just pry the little ball out?

underneath there are 3 little screws....take them out and the cover and the 2 balls will fall right out!
:thumbsup:
 

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To all, on the Raptor Forum, I sent this issue to: Randy K. & Ryan W. (Service Manager & Service Writer, respectively) of Crossroads Motorsports, Gibsonia PA.

Website: www.xroadsmotorsports.com

Lets see if we get some answers.

This message is for

Randy, Ryan and to "All Others",

"All others", I am sending you this, since in the past you were thinking abouting getting yourselves a Raptor 700, with the exception of-course "grayghost" & "type36", you already have one! My only hope with this email, is that we get some answers to this, very important question and or issue, from the folks of Crossroads and ultimately, Yamaha!

Randy & Ryan,

I was in for my first service on Saturday. You may remember, I left my "06" Raptor 700 SE at Crossroads on Monday May 7th, 2007 and picked it up on May 12th, 2007.

I spoke to Ryan about this, when I dropped my Raptor off, along other topic's of issues...I will send you those, later.

Please read this in its entirety: http://www.raptorforum.com/index.php?topic=16018.0

Have you ever heard of this? And can there be something done about it? Does Yamaha, know of this? I too, have experienced this on occassion, and wonder if I am riding a ticking time bomb.

PLEASE ADVISE!

Thanks!

--
SEVEN00

Secretary of Butler County ATV Traction, www.atvtraction.org
Lead - Membership Committee
Certified DCNR ATV Safety Instructor
PAOHV Individual Member
 

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Discussion Starter · #20 ·
thanks seven, lets see what they say!
 
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