[KTMasean]

Fully with Marius on this and I like to add: why do people pull the clutch while on the move and not changing gears?

 

[Johngalt]

The evidence really does point at the clutch or clutch switch. It’s the common factor in all the above. I’d also add that we’ve seen a number of complaints about cutting out or starting issues associated with coasting so this is something to avoid.

Clutch switch, clutch drag - my experience is that these engines are really easy to stall, or a software glitch. I’d suggest unplugging the clutch switch, readjusting the clutch and using more revs when using the clutch and see if any of those changes how often it happens. Just having the revs too low with a slightly dragging clutch might do it.

Yes, I wonder what will happen if you disconnect the clutch switch (wich is really flimsy and cheap looking on my bike) and try riding. If you can ride without it normally, and not stall while coasting then we found the smoking gun and KTM recall can be requested.

 

[STINGRAYJAY]

Hi its a problem across the range of KTM’s, in the EU they have to meet strict euro laws so run the bike lean, if it’s nice and warm (bike that is) you should not see this problem but usually for the first ten or so mins this stalling can happen. I was nearly rear ended when all power was lost approaching a roundabout as I ride usually coasting to roundabouts etc to time not having to stop, I wasn’t impressed lol

 

[Johngalt]

Hi its a problem across the range of KTM’s, in the EU they have to meet strict euro laws so run the bike lean, if it’s nice and warm (bike that is) you should not see this problem but usually for the first ten or so mins this stalling can happen. I was nearly rear ended when all power was lost approaching a roundabout as I ride usually coasting to roundabouts etc to time not having to stop, I wasn’t impressed lol

I lost power on a bridge once with no side curb to roll off to. Got lucky that the truck behind had space to break. Almost died. The idiotic environmental laws will cost lives for nothing as the pitiful amount of exhaust from a bikes in Europe and US doesn’t affect the environment in any way whatsoever. It’s all made up and it hurts people and companies. Politicians don’t care as they just found another excuse to tax and punish people for living and breathing.

 

[STINGRAYJAY]

My mum used to say ‘they can’t tax the air that you breathe’ sadly it seems that they can....

 

[Johngalt]

My mum used to say ‘they can’t tax the air that you breathe’ sadly it seems that they can....

Yes, All taxes that are related to CO2 production are effectively a tax on life as such. The medieval feudal lords are exactly the same as unaccountable political elite today. (They are today’s version of aristocracy).

 

[DukeofSeven]

Is there a fuel cut out sensor in case of accident on these things? Wonder if sharp breaking could set such a thing off?

Rollover Sensor, Location (behind steering head):




Rollover Sensor Connector (viewed from right side of steering head):




Rollover Sensor Wiring Diagram, color codes (A11 equals ECU):



In the case of a vehicle tip-over, yes, the fuel is shut off to shut down the engine.
Could this be the culprit? Yes.
Is it an expensive experiment, as a control variable? No (see next pic; $17.43).



Not as interesting as conspiracy theories... but certainly worth the risk of a 20 dollar bill, even if it's the dealer's 20.
Yes?

 

[discotrash]

So.......... It seems that my duke likes to cut out/stall when braking sharply (with the clutch in) once I come to a stop? Anyone else experienced this at all???

Yes, this happens to me also, simply clutching in and braking sometimes causes the engine to stall, generally in less than ideal circumstances, this is a safety concern, too bad KTM won't release a recall. I should also add, it does this even when not braking. Sometimes simply clutching in and letting the bike attempt to return to idle when coming to a stop kills the engine.

 

[KTMasean]

I believe it is not very realistic to be disappointed over KTM not doing a recall over an issue reported by a few on this forum compared to the thousands around the world riding their Duke/RCs happily.

 

[DukeofSeven]

Sometimes simply clutching in and letting the bike attempt to return to idle when coming to a stop kills the engine.

Interesting.
What i mean to say is, something like that, to me, smacks of a faulty idle control servo, or possibly a faulty position feedback from it(?). And since we are all only 'discussing and hypothesizing' about it, I mean, why not?

Example of why I say that:
I don't know if you guys ever noticed this... but a Duke ETC doesn't work exactly like, say, an automotive Electronic Throttle Body. Case in point, an automotive ETC 'rests' in a partially open position, with no power applied; closing it completely requires electrical power that works directly against a high tension spring. When the key is turned on, the ECU 'closes' the ETC momentarily, in order to reestablish the minimum airflow/minimum authority throttle body position. But unless the ECU 'commands' maximum engine braking, releasing power from the throttle body simply leaves it in a rest open position. The act of 'reducing' idle rpm, in this case, comes from the application of pulse-width modulated reverse current; if it doesn't close when commanded, the system will be disabled entirely and a code will set... but it can't just close on its own.
Right, right, right...

But pull out the air filter lid of a 2017+ Duke 390, and you will see something 'different' when you turn the key on.
Turning the key on results in the ECU powering up, moments later the ETC 'opens' to a startup position.
And if you turn the key off, then watch the throat of the ETC, after a few power-down moments, the ETC completely 'closes'.
In other words, with no power applied, the 'rest' position of the Duke ETC is 'fully closed'. Hmm... that contradicts 'a lot' of sensical convention (about preventing unwanted coast-down stalling or coast-down idle recovery-and-maintenance problems).
Do you understand my meaning here? Perhaps some of you have experience with this.

So, just playing killjoy for a second...
If the gears internal to the ETC were worn in such a way that the plate could just 'flop forward' when you dump the throttle... (but, ah, you'd notice that all the time, wouldn't you?)
Or if the driver somehow got tired, intermittently, of holding the ETC open (but that implies an ECU fault, or an excessive ETC Volt/Amps current situation caused by a borderline ETC windings-integrity condition?)...
Or if the feedback sensor in the ETC told the ECU it was in a slightly erroneous position (but that implies a possible TPS design or production run fault)...
Or if the throttle servo motor just started acting a bit wanky when it got a bit too hot (and who doesn't? especially when forced to ride around all the time 'hugging' a live catalytic convertor)...

Well heck, all of this could even be attributed to an occasionally-skewed ground reference, fcs.
Ok, I'm driving myself nutz.
Please don't let me take you with me.

So without further adieu, maybe in these unique circumstances just related by discotrash and others, I wonder what would happen if we were to temporarily increase the insulation factor between the cat and the ETC unit. Again, it doesn't cost anything is what I'm saying.

 

[TN390ADV]

Was back at the dealer this weekend (after taking off the PT...what a right pain!)
They claimed there was a new and improved software update available that would cure all ailments. Yeah...not really!
Does run just a wee wee bit better without the Coober airbox lid though.
Stalling issue persists. Hot/cold/wet/dry/cornering/straight ahead/stopping/accelerating, no one particular parameter stands out more than the others. Horrible!

 

[KTMasean]

Just to try and figure out your problems, have you ever ridden another but the similar model and year Duke without having these issues?

Was back at the dealer this weekend (after taking off the PT...what a right pain!)
They claimed there was a new and improved software update available that would cure all ailments. Yeah...not really!
Does run just a wee wee bit better without the Coober airbox lid though.
Stalling issue persists. Hot/cold/wet/dry/cornering/straight ahead/stopping/accelerating, no one particular parameter stands out more than the others. Horrible!

 

[TN390ADV]

I did have a Gen 1 390, years ago, that was just a different beast altogether. Smooth, never stalled on me, not even once that I could remember.
This is the first small capacity bike I have owned after that one. My Hypermotard 796, notorious for its own set of problems, did not do anything like this.
I have spoken to a few 2020 D390 owners, who, unless they are completely ignorant and know no better, say "have never heard of such a thing happening."
The dealer just scratches his head.

 

[TN390ADV]

My humble opinion is that if a tune, piggyback, air filter, exhaust, side stand thing, fueling, etc. etc. isn't the problem, then KTM really needs to have a look at this. I am also sure this problem must be affecting thousands of bikes, if not all of them, and not just a few exceptions.
Going around a corner, and the thing cutting off, while locking the rear on a very wet road...not fun.

 

[TN390ADV]

Well, the Coober airbox cover removal and reverting to the OEM one has made a slight difference. Still running the PT unit, so that is enriching it by about 10% or so.
The thing does cut out occasionally, but not nearly as much as it did before.
So this HAS to be related to the drastically lean running condition these bikes suffer from.
I would suggest reverting to a stock filter and airbox lid, if changed, and a PT/RBE/similar and checking it out.

 

[Johngalt]

Interesting.
What i mean to say is, something like that, to me, smacks of a faulty idle control servo, or possibly a faulty position feedback from it(?). And since we are all only 'discussing and hypothesizing' about it, I mean, why not?

Example of why I say that:
I don't know if you guys ever noticed this... but a Duke ETC doesn't work exactly like, say, an automotive Electronic Throttle Body. Case in point, an automotive ETC 'rests' in a partially open position, with no power applied; closing it completely requires electrical power that works directly against a high tension spring. When the key is turned on, the ECU 'closes' the ETC momentarily, in order to reestablish the minimum airflow/minimum authority throttle body position. But unless the ECU 'commands' maximum engine braking, releasing power from the throttle body simply leaves it in a rest open position. The act of 'reducing' idle rpm, in this case, comes from the application of pulse-width modulated reverse current; if it doesn't close when commanded, the system will be disabled entirely and a code will set... but it can't just close on its own.
Right, right, right...

But pull out the air filter lid of a 2017+ Duke 390, and you will see something 'different' when you turn the key on.
Turning the key on results in the ECU powering up, moments later the ETC 'opens' to a startup position.
And if you turn the key off, then watch the throat of the ETC, after a few power-down moments, the ETC completely 'closes'.
In other words, with no power applied, the 'rest' position of the Duke ETC is 'fully closed'. Hmm... that contradicts 'a lot' of sensical convention (about preventing unwanted coast-down stalling or coast-down idle recovery-and-maintenance problems).
Do you understand my meaning here? Perhaps some of you have experience with this.

So, just playing killjoy for a second...
If the gears internal to the ETC were worn in such a way that the plate could just 'flop forward' when you dump the throttle... (but, ah, you'd notice that all the time, wouldn't you?)
Or if the driver somehow got tired, intermittently, of holding the ETC open (but that implies an ECU fault, or an excessive ETC Volt/Amps current situation caused by a borderline ETC windings-integrity condition?)...
Or if the feedback sensor in the ETC told the ECU it was in a slightly erroneous position (but that implies a possible TPS design or production run fault)...
Or if the throttle servo motor just started acting a bit wanky when it got a bit too hot (and who doesn't? especially when forced to ride around all the time 'hugging' a live catalytic convertor)...

Well heck, all of this could even be attributed to an occasionally-skewed ground reference, fcs.
Ok, I'm driving myself nutz.
Please don't let me take you with me.

So without further adieu, maybe in these unique circumstances just related by discotrash and others, I wonder what would happen if we were to temporarily increase the insulation factor between the cat and the ETC unit. Again, it doesn't cost anything is what I'm saying.

Speaking of insulation...the newer Dukes come with exhaust pipe going under the engine. I wonder if newer Dukes have the cut out problem or not.

 

[DukeofSeven]

Yeah. Weird all around.
The only time I, personally, ever had any problem [remotely resembling] what a few guys here are referring to...

is when I was temporarily running a series IAT sensor in my airbox, making the ECU think the air temp was 15 degrees F colder than it actually was. The bike just 'flamed out' on me, once, right in the middle of busy Sarasota traffic, while decelerating -- scared the crapoutta me for sure.
When I got home, I noticed a lotta soot on the outlet of the exhaust, also. The thing was obviously running a bit too fat for its own good, and got confused about howta process it. [not your problem, mine]
I yanked the ridiculous experiment off my bike, reinspected the spark plug, reset the ECU and relearned it. Never had the problem again (and don't want it).

Currently, I'm at around 5600 miles, and still have the original plug and fuel filter installed; no control mods whatsoever.

There is one thing I did do, however, when I had one of the covers off the left side of the bike. There is a system ground that is tied to the frame reference, held tight by one of the coil mount bolts... but it passes through and compresses one of the plastic coil cover mount holes, which I thought was absolutely brilliant. Yeah, that was sarcasm for sure.

I had noticed this when my thermostat came unglued / started leaking, soon after I bought the bike. I took a small file and cleaned away the frame paint where that wire was intended to seat on the frame. The wire wasn't actually long enough to reroute and mount elsewhere, or else I would have gone that route. I thought it was a bit strange of a design oversight...

and possibly what also went wrong with Starship8(?).

 

[Johngalt]

I saw some people claim that the problem is with the faulty gear position sensor.

What is a Pickup sensor? (Stalling cure)

I was reading about the famous stalling issues when rolling to a stop with clutch lever pressed and twisting the throttle. One person said the the dealer had to replace “Pickup coil” or “pickup sensor”. Does anybody know the part number or what it is?

www.ktmduke390forum.com