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Gas tank boiling?

5K views 26 replies 14 participants last post by  z00 
#1 · (Edited)
2015 S1000RR Black

I rode my bike to work today, it sat outside without cover from 6am to 2pm. I left and had an hour long ride home in traffic @ about 85-90 degrees ambient air, 110-125 IAT indication, engine temp never passed 220.

The whole ride the bike was bucking like it was very heat soaked (which is no surprise considering the temps I was noting)

So I get home and leave the bike parked just outside the garage door for the last hour or so just to let it "cool off" before I bring her in.
When I approached the bike I could hear what sounded like a hissing hose, I figured the fuel had expanded and was venting.

Upon opening the fuel cap it didn't vent, but instead I could see the fuel bubbling like it was boiling. The tank was VERY hot and it was audible that the fuel was being aerated. It sounded just like a pot of boiling water.

I have it up on a stand now with a high flow fan blowing directly on it.

Should this be something I should be concerned about?
@bennymx
 
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#2 ·
Take a magnifying glass and go burn a bug with magnified sunlight or your own skin. I wouldn't be concerned from a mechanical aspect(obviously), but I wouldn't leave the bike in the sun to bake. I used to cover my old FZR1000 while at work here in Phoenix during the summer. The carbs vapor locked on me once and I decided to never let my bikes roast in the heat again.
 
#3 ·
I don't think the bike sitting out while at work had anything to do with it, it wasn't doing that when I went to go home. I think the heat from the engine and the sun heating the tank at the same time was what it was. I prefer to burn little green army men, they are a lot less resistant. They take it like a man.
 
#6 ·
Thank you sir! I was just looking different types of foil up haha
 
#10 ·
I used the thermal barrier tape on the underside of the tank. Several layers. Haven't done the airbox but was planning on doing that too even though it is likely unnecessary.
 
#12 ·
100 - 430F
Auto-ignition Temperature: > 536F (280C)
 
#14 ·
Ive been waiting hours for you, Elk, and zoo to come in and say something awesome, despite my initial feeling of a lot of the replies you have to things I have posted, I love to read you guys comments. rider4life is quickly making my list too.
 
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#16 ·
From a mechanical point of view. Boiling the fuel is not an issue. I had a scenario once where some guys I work with were riding in the desert here in Australia and the temp outside was about 50 degrees Celsius (122 for Amercians). This was on F800GS Adventures btw. They stopped and they could hear a hissing sound. They popped the fuel cap and out came a fountain of fuel. Sprayed quite a long way. They got me to check the vent lines and in line check valve. All was fine. They had issues in the US with the plastic tanks actually cracking from all the pressure. The valve didn't allow it to vent quick enough in high heat. Some people removed the valve completely and had it open. As long as the tank is venting adequately enough, there isn't a problem. It's not good to leave the bike in the direct sunlight but I understand some people have no option. So in future if you pop the fuel cap and it sprays fuel out, you may want to check that it's venting properly. Open it slowly and see if you get a rush of air out.
 
#18 ·
A quick internet search and it looks like most pump gas boils around 140-200 F. That surprises me, and Ive never heard of the fuel boiling on a motorcycle. Had it happen on some old carbureted cars. Anyway, I guess its not that uncommon. I do know my HP feels hotter than any bike Ive ever had before. I really want to wrap the headers. I think most of the heat felt when riding has to be coming off of those.
 
#22 ·
I had a black 03 R1 and it would boil on 40 degree days here on the coast if I left it outside after a fast ride.

Have been sprayed with fuel from opening the tank, and I even tried to open it slowly but the pressure was so strong. It was hissing like a snake and then it spat like one.

That bike was a hot bike.
 
#25 ·
Boiling fuel is scary but quite common. I have had it happen on a few bikes I have owned. My MV Agusta F4 and an old FZR400/600 hybrid.

As many have mentioned the boiling point of gasoline is low. You have a black gas tank. What has not been mentioned is pressure helps raise the temperature. Like a pressure cooker. Checking and perhaps even cleaning the vent lines for the tank may help. The foil will help as well. Home depot has a foil backed "bubble wrap" style of insulation that worked well on my MV Agusta to insulate the tank from the engine's heat.

RR's get hot in their stock configuration. Modify any of the fuel injection maps and they have the potential to get hotter. I notice a huge difference in the amount of heat my stock RR puts out vs my RR with the HP Race ECU.

It's important to keep in mind as well the temperature required to ignite gasoline. It's a lot higher than you think. My MV Agusta had a failed fuel fitting start to POUR fuel on a very hot engine while I was riding. Despite the heat of the engine the fuel did not ignite. Although I was not taking any chances and the moment I arrived home I rode straight to the garden hose and got as much water as I could all over the bike. :)
 
#27 · (Edited)
Trace tank fuel vent hoses and ensure they're breathing. Air filter housing sits very close to vent lines, especially clutch side, if not installed correctly it could block venting. Also, ensure hoses are plugged tight into the tank, I have seen it before when people don't plug the hoses tight.

You can find a small bike cover for around $35. Which blocks heat/UV. I would get one and cover the bike if it's gonna be sitting in the sun for a while. Cover is small. Especially that you have a black bike. Search for posts by me, I my cover on Amazon and it's great, even for just covering bike while in garage.
 
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