Gas tank pressurised

[AllanP]

I took my 500 mile SD-GT out for its second ride yesterday in temps of about 85F. I stopped for gas switched off the ignition and when I opened the gas filler cap there was a huge out-rush of air and gas fumes which can only have come from the gas tank being under considerable pressure

This was accompanied by a warning on the combination instrument which said "Fuel Pump Failure".

I was in the middle of nowhere at the time so I had to try to restart the bike which I did and it ran perfectly. I rode a mile down the road, stopped the bike and opened the gas cap again, no pressure. I rode all the way home and carefully opened the gas cap, (outside and away from my house) and no pressure this time either.

On older bikes, I've seen a slight vacuum form in the gas tank if the air bleed to the tank was obstructed but never seen or heard of any condition which could put the tank under such great pressure. Anyone seen this or have any idea what it might have been?

[linehand]

I've seen the gas tank vent check valves on other bikes not do their job and result in what you experienced. I'm sure Ktm would warranty it for you but the new one could be just as problematic. Easy enough to cut it out and just have a free flowing vent if it keeps giving you problems.

[DaveNZ]

If you do the Rottweiler stage 2 SAS removal kit, it illiminates a lot of the E4 shit. I've done mine, and you can use some of the origonal pipe work to fit 2 breather tubes

[Tancakar]

sas normally cause this sometimes . also check your coolant . ask them to change your fuel pump.

[JDS1290SDr]

^^^ WHAT, Check your coolant, ask them to replace your fuel pump? That's crazy. The service manager would laugh you out of the shop.

Allen, check your fuel tank overflow hose. I suspect it was plugged. On my 2015 1290 SDR it is on the left hand side of the bike at the back of the tank, bottom of course. I believe it is routed to just under the gas cap. Any pressure or vacuum should be relieved through that.

[AllanP]

^^^ WHAT, Check your coolant, ask them to replace your fuel pump? That's crazy. The service manager would laugh you out of the shop.

Allen, check your fuel tank overflow hose. I suspect it was plugged. On my 2015 1290 SDR it is on the left hand side of the bike at the back of the tank, bottom of course. I believe it is routed to just under the gas cap. Any pressure or vacuum should be relieved through that.

Will do, thanks.

[DaveNZ]

^^^ WHAT, Check your coolant, ask them to replace your fuel pump? That's crazy. The service manager would laugh you out of the shop.

Allen, check your fuel tank overflow hose. I suspect it was plugged. On my 2015 1290 SDR it is on the left hand side of the bike at the back of the tank, bottom of course. I believe it is routed to just under the gas cap. Any pressure or vacuum should be relieved through that.

JD, the GTs have E4, so all the fumes from the tank get sucked through to the charcoal canister. Ive removed my E4 and SAS system, so now i have a drain pipe and air vent coming from the tank,and from the over fill flow down and out the bottom. Tancakar could be right in that little pump and the SAS system could pressurise the tank if not working properly, but highly unlikely. So the tank vent system is through a hose that goes to a little motor then to the charcoal canister.

[JDS1290SDr]

^^Ok. Interesting. A little vacuum pump to suck the fumes out? That's what all that crap was?
My SDR may have had something similar.
I can understand the concern of buying a NEW bike & having all these little unknowns. It shouldn't happen & it would be a piss off.

[DaveNZ]

^^Ok. Interesting. A little vacuum pump to suck the fumes out? That's what all that crap was?
My SDR may have had something similar.
I can understand the concern of buying a NEW bike & having all these little unknowns. It shouldn't happen & it would be a piss off.

The bikes we get in NZ don't usually have this charcoal canister vent system, i think the GT is one of the first bikes here with the E4 and this tank ventilation system, i removed mine and did the SAS block of plates at the same time, i think the motors work a bit like a tropical fish tank air pump motor, more like a vibrating type suction. It all weighed about a Kg, so it was good to be rid of it. it also gave me more room under the seat for a puncture repair kit.

[JDS1290SDr]

Do you mean like these Dave? Plus the hoses & other crap.
I think that stuff is common on both bikes??
That flapper valve in the exhaust is another story.
Hopefully Allen has his GT working well. Little issues like what he is having can leave a bad taste in one mouth.

[DaveNZ]

Yip JD, your 1290R canister and pump look very similar to mine, A Bosch pump? Have a power supply?, Mines slightly different, the hose comes in one side and exits out the other. I think these have been on Californian model bikes for years, we are just starting to see them on bikes down here. When i removed mine, i used some of the spare pipe to fit a vent pipe and run it with the drain pipe that takes away any over fill of fuel.

[AllanP]

Thanks for all the input. I had it at the dealers for its 620/1000 service yesterday and the service manager told me that this phenomenon is not unknown and as some of you rightly suspected, he thinks its connected with the system which purges gas laden fumes from the tank into the charcoal canister.

When we normally fill the bike with gas, we switch off the ignition which shuts down the purge system and immediately open the tank - no time for pressure build up, no problem.

If we stop for gas, switch off the engine BUT DON'T open the gas cap immediately, the purge system will still shut down but the heat from the engine, especially on a hot day, will heat the tank. The gasses inside have nowhere to go and when we open the gas cap, all of that pressurized air will escape.

When I got to the gas pump, I switched off the ignition, used my credit card to buy gas and only then discovered that that particular pump was empty. I then pushed the bike to the next pump (without switching on the ignition) only to discover that this pump was empty too. I finally discovered one pump that did have gas and by the time I pushed the bike to that pump and entered my credit card number, the bike had been standing for some time with the purge system switched off. It was on a hot day, the tank had been cooking on top of a hot engine with no where for the gasses to go and the tank became pressurized. This seems to be a logical explanation and I'll know how to avoid it in the future.

Taking off the purging system, (don't know what this is called in an SD-GT) may be an option but I need to get to know the bike better first, do some research and only then consider pulling stuff off.

[DaveNZ]

Great news Allen, that was what i thought might be happening something along those lines. Further down the track you could do the Rottweiler stage 2 or stage 3 removal kit, for the SAS plates and system and the charcol canister removal, gives you more room under the seat for storage.

[Loomster]

I had to wait a day to pick mine up this week because of this exact issue, KTM were not releasing any Superdukes until a different breather pipe was fitted. I'm not sure if there will be a recall or not, you would think so wouldn't you?

[Tancakar]

if a bike giving fuel pump failure, they will check the fuel pump nothing else. KTM fuel pumps are quite bad, i already got a problem.

[AllanP]

Hmmm.........that's interesting. My bike has never done that since the first and only time but it was pretty alarming when it happened. I'm still waiting for the part to arrive to change the torque limiter but I'll raise the fuel tank pressure issue with the dealer again and see if they've heard anything. Unless KTM knows something they can share it could be very difficult for the dealer to pin point because its was a one-off occurrence on my bike.

The bike has 3097 miles/nearly 5000 km and is running the best it ever has. I still have the torque limiter screech every now and then when I try to start it and sometimes it won't turn over when I press the starter button but it runs beautifully and the list is getting shorter

[OldGit60]

"I still have the torque limiter screech every now and then when I try to start it and sometimes it won't turn over when I press the starter "

Following on from AllanP , my starter shrieks occasionally - more so when hot - and is booked in to be checked out. Is this a normal/common phenomenon?

[AllanP]

OldGit60 (I'm an even older Git!)

The dealer replaced the starter torque limiter on my bike at 3444 miles. Its got 5300miles/ 8480kms on it now and the starter has never made any noises since the repair was done. Because the shrieking noise could be made to go away by changing a part, I'm calling this a fault. It may or may not be "normal", but it is fixable.