I'm looking on behalf of a friend. We were travelling together but he's now off on the last leg of his trip and the bike is playing up rotten. While riding together it started "choking" as he put it. It was like the power was running out, an air blockage maybe or dead plugs. As it got hotter it seemed to get worse, stuck in traffic it would barely stay running. It cut out, spluttered, lost all power and then just died. We couldn't find anything wrong then it would start and run and then as it got hotter, it just did it again.
When we got to Bangkok it had a full service. They put it on the diagnistic and nothing wrong. I was suspicious but the bike ran fine after they cleaned it up, we hoped it was just a lot of dirt in the radiator. Now once he put the panniers on it did it again. At first we were stuck in traffic in bangkok so I thought maybe it was that but he swore it was the boxes. Possible I guess, they block airflow to the exhaust where the O2 sensor is.
Now he's right back to square 1. It's cutting out even when not in traffic. Once the weather cools or he drives in rain it gets better. He has bridged a circuit over the temperature sensor and said it helped a bit but only the rain and riding in the night when it's cooler keeps the bike moving.
Does this sound like anything anyone recognises? I'm not a KTM man and not familiar. Thanks guys.

Probably the fuelpump.

Interesting, other people are telling me this. Is it a typical problem with these?

Hola amigo

I am now in south america and had exactly the same problem.
read a lot in forum and many people try simply to say it is the fuel pump.
This is expensive.
So I got from KTM in Santiago the Chile a fuel filter set.
Most importend is the intake filter of the pump. It looks like a tee bag.
When this is clogged the bike behave like this.
since I changed the filters (the are 2, intake and outlet) the bike is running fine.
There are also excellent descriptions on adv rider. Look after fuel pump 990

good luck....

Fuel pump.

As heats up, pump malfunctions and output drops. Does it happen as tank gets lower in petrol (used for cooling the pump)?

Similar symptoms to F800GS issues.

I can't answer very specific questions as it isn't my bike but it did do it with a full tank and then we lost a lot of fuel investigating the problem and it was still bad. It didn't do it so bad the next day after filling up and riding while it was cooler. It was far better through Nepal too but it was cooler in the mountains.

Your problem is whit pump

You can fix it disasamble complete and wash the internal filter whit clean gasoline.

If you are not advanced mechanic, poor same two stroke oil into the left gas tank and your problem decrease.

The complete solution is clean or change the internal gas filter pump.

good lucky

Hey,

Its the Fuel filter for sure, had the same problem in Iran the bike slowly dies and get worse as the day goes on, you need to watch you have not done to much damage to the pump but it should be ok, you need to change the fuel filter asap, Go to KTM in bangkok they should have one, including the rubber ring you need to replace. I now filter all my fuel all the time through a tea strainer and it is shocking some of the crap i have stopped going into my fuel tank.


Good luck.

James

__________________
Mr and Mrs Rixxy - London to Australia 2011 - 2012
www.jamesandcat.com

Have had the same problem. 2 problems, actually.
Either the fuel filter is choked and will need replacing, the fall-off in power was quite noticeable at highway speeds with a low fuel tank level, refuelling fixed
that problemo, only temporarily though.
or:

On a very hot day, slow heavy-going climbing with the fan running, I'd feel the bike either miss on one cylinder or get sluggish.
This seemed to be due to vaporization of the fuel on it's way to the injector.
The L.H.S tank forms the cooling fan duct. The pump is inside this tank.
A stop and a drink to cool the rapidly overheating rider seemed to be the fix, as the bike stopped misbehaving and no problem suffered from then on.

Hi,
had the same problem travelling in Morroco. dirty fuel clogged the filter and had to service it to continue my trip.
found these interesting links on how to do it:

990 Fuel Filter Replacement - ADVrider

and this one more detailed:

ADVrider - View Single Post - 990 Fuel Pump Filter How-Too

cheers

Have you checked that the air pipes to the fuel tank are not pinched by the two top fairing pieces please?
When putting these bits back on it's very easy to trap the rubber pipes, so stopping the tanks venting... easy to find out- when the problem occurs open the tank filler cap, if you hear it suck a load of air in it's the pipes trapped.
Hope this helps, had this problem on my 950 the fuel pump - never touched it in 71,000 miles.
Cheers
Col

Fuel pump...

Just did mine last month. Buy the filter kit only, do not replace the pump unless you like tossing tons of money out the door. Make sure your kit comes with the O-rings. Do not buy the O rings from KTM.

Once out of the tank, take a look at the black wire's connection inside the bowl at the bottom. This wire has a bad crimp and can slid off the connection while inserting the pump back into the tank. Aside from having dirty filters, this wire will also make the bike cut out randomly if it's not securely connected. When installing the pump, put a light coat of grease on the tank plastic to allow the o-ring to slide in with ease. Replace it slow and steady until seated or you may damage the o-ring.

Good Luck

iv seen afew guys having problems.
two guy set on rlw on ktm 690 i think, both had problems with pump, theye started siving fuel on filling, and all was fine then

Its the fuel filter in the tank. It gets clogged by dirty fuel. The symptoms are the bike chokes under acceleration, but the problem can come and go. It is best to sort it out before you damage the fuel pump. It is quite a major job, not a road side repair.