Went out this morning and started bike. Same procedure. Thirty seconds and lights start to flicker. One minute - fuel pump failure and bike stops. Cycle through the start up process and bike fires up and runs normally. Engine warning light also went out.
Bike booked in with dealer for next week. During the discussion I mentioned that I had recently fitted a new Li ion battery. Dealer thought this might be related as they do not recommend Li ion for 1290 SAS. Strange then that it was sold to me by another KTM dealer who said they were moving away from lead acid. Anyone got any thoughts on this?

Nigel

 

Moving away in that enduros run lithium batteries perhaps.

Still can't see why that would cause a fuel pump to fail?

Possibly clogged filters as that is something well known to strike at low mileages occasionally.

Or just one of those random electrical issues that will dumbfound the dealer and have them swapping parts for weeks, in which case be thankful its not your pocket picking up the tab for their inability to fault find!

 

I like to be optimistic, but I suspect you may be right. I'm going to put the original lead acid battery back on and see what happens. At least that will be one variable tested.

 

If anyone is sufficiently bored to be actually following this thread then I think (hope?) I have a happy ending. After what AMS said about not recommending Li Ion I replaced it with the old, and fully recharged, lead acid battery. Bike starts and runs fine with no warning lights. I've tested it on three occasions across three days and no issues at all. Seems they may be right. Fingers crossed.

Nigel

 

Very interesting, maybe if it aint broke,leave well alone ..

 

I think all the big KTM fuel pumps are a bit shit; my money is on repeat failure of it, till it eventually dies... The Quantum replacement pumps are meant to be a bit better.

But here's hoping you fixed it!

 

Pretty sure it's not the pump. Since putting the old battery back on it's been faultless. Also remembered that I had the Li battery on very briefly last summer and had the same 'fuel pump' failure warning light. My guess is it's something to do with the charging of the battery which then translates into a failure at the pump as the voltage drops, as t's not just the pump that has problems but the headlights as well I'll get them to read the fault codes at the next service.

 

This is interesting to me... for a while I've been reading up about "upgrading" bikes that were designed to run lead acid batteries with Lithium batteries.
The chemistry makes sense, in respect to the batteries operating & charging voltage levels, but I'm not convinced that a small lithium battery has the same damping effect on the stators output as a much larger lead acid battery has.

The damping effect of the battery (its ability to absorb voltage spikes) is very important for a permanent magnet and stator type charging system.
If the battery can't absorb the spikes fully then the voltage peaks get too high and regulator has to fire, when that happens the stator output gets shorted and the battery has to carry it until the next stator phase starts to give sufficient output. This will produce a very choppy DC voltage output which might work ok on a single that has basically no electronics but on modern bikes, with multiple ECU's you are asking for trouble, unless the bike has been designed to incorporate a lithium battery.

I think I will be keeping my lead acid batteries on my 990 and 1190... but for my DRZ400 the next battery (coming soon) will be super capacitor.

 

Excellent explanation. Although more a materials engineer than electrical I can follow what you say. Certainly the flickering of the headlights and dimming of the display just before the engine dies and fuel pump warning appears seems to point to disrupted supply right through the sytem.

 

My Husky puts me of Li for big bikes, started it the other day, it was about 5-6c in the garage and the battery was topped up, whelled bike out and hit starter and no go, the procedure is to turn over for @3 seconds, wait 30 seconds then repeat, this warms the battery, it started on the 3rd stab of button, in summer it just starts 1st time.

Knowing this is "normal" does help, but fuck going through that on my 1290 high up somewhere in an alpine hotel, even if it does always start eventually, your gonna look like a knob with a fucked bike to everyone else, and then when people offer to help, give you a jump / push you have to explain you are warming your infinately superior battery.

As for the weight savingm just eat a few less pies / pizza's / kebabs for a month, I have just had a chest infection and lost 5kg in 2 weeks, if I get another similar ilness I can flog my Akra.

 

KTM 1290 super duke r 2017 Maybe someone knows. I was driving, suddenly I started to triple and stalled. Then I stopped starting, I gave an error on FUEL PUMP FAILURE, I changed the pump, I still didn't sell, it's not worth the native battery

 

Did you change the two fuel filters too? These should have come with the pump.

 

Yes, I changed the fuel pump, changed the battery and still didn't h

 

I also have a 2020 1290 SAS. I replaced both the fuel pump with a Quantum late last fall in 2023 and also upgraded to an EarthX LiFePO4 battery. Major improvement in starting performance. However I experienced the exact same issue as NigelG. I have been out twice so far (once last fall before putting it away for winer) and today on a warm day and the bike dies after riding for 15-30 minutes with a Fuel Pump failure light. Pretty sure it can't be related to the fuel pump since I just replaced the entire thing with a new one. So I shut everything down and restart the engine. No issues after doing so and no warning lights. Start riding again and the same issue occurs 15-30 minutes later. I had an EarthX as well on my older 1190 SA for a few years and had no issues also with the upgraded Quantum fuel pump. The battery was so much better than stock. Well guess I will put on my original gel battery and see what happens. Bummer as the weight is so much lighter and starting performance much superior.

 

Apparently the issue is the drop in voltage in the Li Ion battery after starting. It may seem better starting than the conventional battery but the energy needed to do this takes some time to replace and with the bike running a myriad other electric functions, including daytime running lights, the battery can't replace this quick enough. Forget about the weight saving. If it was a 125cc racing snake it might matter but the 1290 is a 240 Kg lard arse with 80 to 100Kg of rider on board. The lighter battery makes bugger all difference. Go back to the OEM battery. I've not had another issue since I did. Latest it not always greatest.

Nigel

 

Read a few reports of big KTMs not liking trees batteries so replaced mine with same Yuasa as OE.

 

I've been struggling with a similar issue to NigelG, catalogued here... Yesterday I replaced the fuel pump with the comprehensive QFS kit; pump, filters, O rings, pressure regulator, took it for a test ride and after the usual four miles or so my old friend "Fuel Pump Failure" made its customary appearance. This thread has got me thinking, as I replaced the dying battery on my 2018 SDR with a Noco Lithium lobby last summer - starting has been brilliant since, and there were no fuel pump issues at all until a couple of months ago. The issue I get is consistent, always starts about 4 miles from home, bike always restarts on the button instantly, and it varies between one occurrence (first time) and 22, always eventually clearing after dicking about for a few miles and not happening for the rest of the day, no matter how long I might leave the bike between journeys that day.
Annoyingly I did a tip trip a few weeks back and took the five bike and car batteries that have been replaced recently to the recycling centre. Had I been aware of this thread I could have tried charging up the old gel battery one more time and giving it a test to see if it made a difference. After blowing £180 on a fuel pump kit that it turns out I didn't need, I'm not too eager to throw another £80-odd on a hunch. need to borrow a gel battery from someone to see if it's the answer.