I've heard about this on various forums, apparently it's the heat from the engine boiling the petrol which creates a lot of pressure as you know. Seems to happen in extreme heat which I guess they don't get in Austria... Anyway, people put that adhesive heat reflective material on the under side of the tank to help. The lack of R&D on ktms newer bikes is painfully obvious, lots of silly issues that are generally easy to fix.
Holy crap! That's definitely not good. Might be all those times that you keep dropping the thing or riding it under water. :-p What's with the strange blue things on your arms? Don't you know that it's summer? HaHa!
had the same issue with mine. problem was two fold. First. the vent tube that travels back to the canister in the rear was crimped by the seat support. i repositioned the line and that helped. 2nd. there is a tiny ball at the fuel cap that stops fuel from running out if the bike goes horizontal. when the pressure builds up it seems to lock that ball in closed position. i had my fuel blow all over me and the HOT bike while in the middle of back wood Smokey Mts in Tenn. I could have burned alive if it had ignited. Solution was to reposition vent tube so the seat in low position did not crimp vent tube. Very Dangerous!!!. i plan on removing that worthless vapor canister soon any way.
Yes, I removed that tiny ball. So now when my bike is upside down (not more than once or twice a ride ;) ), fuel dribbles out of the tank cap. But that is the better solution that the tank volcano option.
I had a 2013 KTM 1190 with the same problem. You could see fuel vapour streaming out at the bottom of the vent tube. KTM did a service mod for the tank filler cap vent and also some heat reflective material under the seat (for the rider, not the tank), but it was still an issue on hot days.
Today had plans for a nice ride... got about half way and parked under a tree in the hills with a nice breeze and watched the day go by. Packed lunch and frozen hydration pack worked out nicely.
Yes, the little ball bearing in the breather (inside the cap) gets stuck. Its meant to let gas out but not fuel. Anyway, I removed the ball bearing. Now, when I fall over, fuel leaks out of the cap, but it has never pressurised like that ever again.
Was this the breather for the petrol tank? My honda cr250 was running really bad so I took the petrol tank breather off and it was blocked with a little plastic ball. I blew it out and it ran perfectly. Was that little ball surposed to be in there?
An oldie but a goodie. Here's to the almightly algorithm. Anytime there is a canisterectomy you've got to vent, both ways. 990A has a known issue with this, the HOW helps you mod the tank breathers in the caps. Kove 450R has the same issue, two way cap vents are the solution. Riding in 5c happened on the Kove due to off-road movement, not heat. Pressurized both tanks and forced fuel from right to left tank. Bleeding off the right tank to prevent a geyser was the workaround. Two-way vents were the fix.
maybe your breathers are clogged....so while you were using the bike, the fuel pump was sucking fuel that induced a vacum inside the tank, once you have vacum the fuel starts to boil not because of the vacum only but because of the heat too, and when you open the cap the fuel was boiling and the air from outside was coming in because outside the tank the pressure was higher so, you had 14,69psi of air coming inside the tank through a hole less than 3”. Summarizing, a real mess!
Much like a boiling radiator, when you reduce the pressure (and thereby lower yhe boiling point) it either starts boiling or boils more violently! In both cases better to wait it out if you possibly can.
just saw other post below repeating my same comment. What happens when using the phone and not big screen. Anyway would like to see how you removed the valve at the tank.
+Nerb1 I took a video of how I vented my tanks on the 990.... maybe our bikes are different enough that it wont work with yours.... I'll try to find it, or the parts of it, and put it together for you to have some reference. I have no pressure problems with my bike, and it vents out way high up above the headlight actually. I did it when doing my cannisterectomy and the SAS mod. Be patient with me, but I'll try to find it.
wow, never seen a tank get that much pressure before, didn't know that the fuel boiled out like that, thanks for the tip, I think I would have made the terrible mistake of just opening it!!
+ratsac Cars with semi/blocked breather hoses do that, generally breather hoses contain a spring and little ball bearing/valve that allows flow one way over X pressure. Just like all things can get gunked up and reduce/stop working.
Mine did the volcano routine also. I removed the sas system and didn't remove the plug in the vent tube. I sealed the tank and when I went to add gas it flew up about a foot in the air and lost about a half gallon. Scary to see happen when the bike is hot but once I removed the plug its been fine. Don't know if you have the charcoal canister or not but definitely the vent is blocked off.
We dont have that canister on the Australian model. But I gutted the overly complicated breather system and it has been good ever since. I think the tank breather is set up to stop fuel running out when the bike is on its side, but simultaneously let pressure out. The holes are so small it blocks very easily.
he's actually getting suction here. The eruption would come from the rapid equalization of pressure since the vent is blocked. As gas leaves the tank no air is coming in, creating negative pressure.
hey, yea I have the same issues and opened the cap up and someone had installed the seal wrong and it was blocking the vent hole. so fixed that and per your advice :) remove the ball bearing thing. at some point someone had snapped the drain hose nipple and tried to glue it in and blocked that so now I hope this will be a thing of the past, but i thinking of changing out the gas cap all together. But I hope I got it taken care of for now! ktmtwins.com/products/cj-designs-billet-fuel-filler-neck-ktm-1190-1290-adv?gclid=Cj0KCQiAv_HSBRCkARIsAGaSsrDdUzLB2h3NL0n-rqhpck_3V8TX70g-K4AG9_Ftjql4mhPXbFax-9AaAuakEALw_wcB
I've heard about this on various forums, apparently it's the heat from the engine boiling the petrol which creates a lot of pressure as you know. Seems to happen in extreme heat which I guess they don't get in Austria... Anyway, people put that adhesive heat reflective material on the under side of the tank to help. The lack of R&D on ktms newer bikes is painfully obvious, lots of silly issues that are generally easy to fix.
Well, sometimes when life get a little heated, you just need to let off some steam.
Holy crap! That's definitely not good.
Might be all those times that you keep dropping the thing or riding it under water. :-p
What's with the strange blue things on your arms? Don't you know that it's summer? HaHa!
Yeah... I was on a job site that requires long sleeves! Spent the rest of the arvo just in my undies!
That's crazy, it was just like an overheating radiator.
Hooooly crap... thats fuckin scary
had the same issue with mine. problem was two fold. First. the vent tube that travels back to the canister in the rear was crimped by the seat support. i repositioned the line and that helped. 2nd. there is a tiny ball at the fuel cap that stops fuel from running out if the bike goes horizontal. when the pressure builds up it seems to lock that ball in closed position. i had my fuel blow all over me and the HOT bike while in the middle of back wood Smokey Mts in Tenn. I could have burned alive if it had ignited. Solution was to reposition vent tube so the seat in low position did not crimp vent tube. Very Dangerous!!!. i plan on removing that worthless vapor canister soon any way.
Yes, I removed that tiny ball. So now when my bike is upside down (not more than once or twice a ride ;) ), fuel dribbles out of the tank cap. But that is the better solution that the tank volcano option.
Wow, never seen it that bad...
I had a 2013 KTM 1190 with the same problem. You could see fuel vapour streaming out at the bottom of the vent tube. KTM did a service mod for the tank filler cap vent and also some heat reflective material under the seat (for the rider, not the tank), but it was still an issue on hot days.
That's a lot of of pressure
Today had plans for a nice ride... got about half way and parked under a tree in the hills with a nice breeze and watched the day go by. Packed lunch and frozen hydration pack worked out nicely.
Dude that looks dangerous... did you ever get it fixed or find out what was causing it?
Yes, the little ball bearing in the breather (inside the cap) gets stuck. Its meant to let gas out but not fuel. Anyway, I removed the ball bearing. Now, when I fall over, fuel leaks out of the cap, but it has never pressurised like that ever again.
Was this the breather for the petrol tank? My honda cr250 was running really bad so I took the petrol tank breather off and it was blocked with a little plastic ball. I blew it out and it ran perfectly. Was that little ball surposed to be in there?
An oldie but a goodie. Here's to the almightly algorithm.
Anytime there is a canisterectomy you've got to vent, both ways.
990A has a known issue with this, the HOW helps you mod the tank breathers in the caps.
Kove 450R has the same issue, two way cap vents are the solution.
Riding in 5c happened on the Kove due to off-road movement, not heat. Pressurized both tanks and forced fuel from right to left tank. Bleeding off the right tank to prevent a geyser was the workaround. Two-way vents were the fix.
Fuckingggg hell!!!!!! That was so dangerous
maybe your breathers are clogged....so while you were using the bike, the fuel pump was sucking fuel that induced a vacum inside the tank, once you have vacum the fuel starts to boil not because of the vacum only but because of the heat too, and when you open the cap the fuel was boiling and the air from outside was coming in because outside the tank the pressure was higher so, you had 14,69psi of air coming inside the tank through a hole less than 3”. Summarizing, a real mess!
This very dangerous, especially if you are smoking a cigarette
My old Lawn Tractors fuel used to boil. I gave it away, Yep that is not good at all. I would be so scared it might blow up on me. I would not ride it.
Much like a boiling radiator, when you reduce the pressure (and thereby lower yhe boiling point) it either starts boiling or boils more violently! In both cases better to wait it out if you possibly can.
My moped gas tank wasn't getting any air.Pressure was building up my moped would stall wouldn't start up.Got it fixed and it runs better now
I see your problem. It’s stamped on your handlebars. Thank me later.
just saw other post below repeating my same comment. What happens when using the phone and not big screen. Anyway would like to see how you removed the valve at the tank.
Same thing happened to me and it exploded all over the place. It hasn't happened since.
Bloody hell.... I was waiting for it to go bang!!
My face saw it that bad yesterday. If you get it in your eyes - immediate water water water.
Wow dude..... Your tank is not breathing bro..... Have you done any vent modding yet on your bike?
+MrDuhfactor No I havnt. It has a breather, but im assuming its blocked at the moment. What sort of mods can be done?
+Nerb1 I took a video of how I vented my tanks on the 990.... maybe our bikes are different enough that it wont work with yours.... I'll try to find it, or the parts of it, and put it together for you to have some reference. I have no pressure problems with my bike, and it vents out way high up above the headlight actually. I did it when doing my cannisterectomy and the SAS mod. Be patient with me, but I'll try to find it.
Its not in the cannisterectomy video, ive seen that one. I'll keep looking :)
wow, never seen a tank get that much pressure before, didn't know that the fuel boiled out like that, thanks for the tip, I think I would have made the terrible mistake of just opening it!!
+Andy Pandy Motovlogs watch everides video here: ruclips.net/video/MfDs2W6-Awo/видео.html
Cars do this all the time when you open the fuel cap. I would have though the breather only has a one-way valve to stop *negative* pressure?
+ratsac Cars with semi/blocked breather hoses do that, generally breather hoses contain a spring and little ball bearing/valve that allows flow one way over X pressure. Just like all things can get gunked up and reduce/stop working.
are you sure it wasn't just your wall climbing cat hiding in the tank?
+Sweetman She was hissing and spitting at me.... possible. Ausmodica told me your fb is gone? You should turn on your skype more often
+Nerb1 yeah too much nonsense on Facebook. I'll try to get on over the weekend
Mine did the volcano routine also. I removed the sas system and didn't remove the plug in the vent tube. I sealed the tank and when I went to add gas it flew up about a foot in the air and lost about a half gallon. Scary to see happen when the bike is hot but once I removed the plug its been fine. Don't know if you have the charcoal canister or not but definitely the vent is blocked off.
We dont have that canister on the Australian model. But I gutted the overly complicated breather system and it has been good ever since. I think the tank breather is set up to stop fuel running out when the bike is on its side, but simultaneously let pressure out. The holes are so small it blocks very easily.
Just short of a BLEVE ?
One of my old bikes used to whistle through the fuel breather. It was weird.
+Scooter Hoon It was doing its job.. and letting you know it is almost blocked.
I understand it was venting. I did some research and apparently the whistling was normal for that bike.
Kawasaki? It is normal then :p
Mine is doing the opposite instead of spewing out I get suction but then it's not a bike
he's actually getting suction here. The eruption would come from the rapid equalization of pressure since the vent is blocked. As gas leaves the tank no air is coming in, creating negative pressure.
Tool ;)
The best!
hey, did you ever find a solution?
Yes. I took the ballbearing out of the breather valve and it has never happened since. Its in the little white box attached to the cap.
hey, yea I have the same issues and opened the cap up and someone had installed the seal wrong and it was blocking the vent hole. so fixed that and per your advice :) remove the ball bearing thing. at some point someone had snapped the drain hose nipple and tried to glue it in and blocked that so now I hope this will be a thing of the past, but i thinking of changing out the gas cap all together. But I hope I got it taken care of for now!
ktmtwins.com/products/cj-designs-billet-fuel-filler-neck-ktm-1190-1290-adv?gclid=Cj0KCQiAv_HSBRCkARIsAGaSsrDdUzLB2h3NL0n-rqhpck_3V8TX70g-K4AG9_Ftjql4mhPXbFax-9AaAuakEALw_wcB