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Discussion Starter · #1 ·
My new 2020 790 Duke, at less than 300 miles, has one very annoying problem. At low speeds the bike will not proceed smoothly. It jumps ahead then slows, all very suddenly and gets worse if you try to persevere. Its fine at idle or accelerating briskly. Hasn't been to the dealer yet, but in a phone conversation, they suggested its normal for a high performance engine. I don't believe it! Comments please.
 

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It's normal for emission controls on modern bikes :) I would suggest you just get used to it, especially if this is your first ride by wire bike
 

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Discussion Starter · #3 ·
It's normal for emission controls on modern bikes :) I would suggest you just get used to it, especially if this is your first ride by wire bike
It is indeed my first ride on a modern bike. I must say, if you are correct, that I'm amazed that anyone would put up with it. Thanks for your comment.
 

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What mode are you running it in at low speed? If I'm spending significant time in city stop and go traffic, I'll put it in rain mode which smooths the response somewhat. It should improve as the motor beds in too.
I'm the opposite and prefer Sport in traffic because the pickup is so much quicker. That's the good thing about having options!
 

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It's normal and due to emission regulations. It can be sorted with a booster plug or a power commander, but will invalidate your warranty. You'll need to learn to ride round it. Play with modes. Some work for some, as previous comments suggest.
 

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It is indeed my first ride on a modern bike. I must say, if you are correct, that I'm amazed that anyone would put up with it. Thanks for your comment.
hang in there it gets better and you'll get used to it it likes to be in the 4000 rpm up range, I find myself riding in third gear a lot around town rather than fourth
 

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All the previous comments are valid. You will get used to it. Keep the revs over 3500 or using Rain Mode in slow crawling town traffic. It will also feel better after its first service, when the dealer will unleash and optimise the ECU.
Sadly the jerkiness is the sting of Euro 5 exhaust emissions regulations, that has forced KTM to run at slightly leaner than 15:1 air to fuel, which is too low for optimum performance. The engine would run better at around 14.2:1.
Also, straight out of the box and during your initial "running-in" period, don't ***** foot around. Get the throttle at least half open regularly - it is vital in the very early miles that pressure is exerted on the piston rings to help them bed in, before glazing and incomplete compression take place. So throttle on/throttle off will help enormously. Don't flog it without a break but don't cruise gently along on fixed throttles either. You won't break it! I've done this with all my bikes and engine rebuilds and they all burned no oil and gone like stink. Sorry to deviate slightly from your initial thread. Enjoy!
 
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Discussion Starter · #9 ·
What mode are you running it in at low speed? If I'm spending significant time in city stop and go traffic, I'll put it in rain mode which smooths the response somewhat. It should improve as the motor beds in too.
I've tried all the modes except track. Not much difference between them. Unfortunately, it'll take a while to get more riding weather here, but we'll see how it goes. I hope it can be resolved because I like the bike otherwise. Thanks for your comment.
 

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It's normal and due to emission regulations. It can be sorted with a booster plug or a power commander, but will invalidate your warranty. You'll need to learn to ride round it. Play with modes. Some work for some, as previous comments suggest.
I wouldn't waste my time with a booster plug. I tried it and it didn't solve it.
 

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It's normal. They run really lean below 3000rpm for emissions. Mine surges pretty bad. I live on a military base with a 20mph speed limit and it struggles.
 

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I wouldn't waste my time with a booster plug. I tried it and it didn't solve it.
It would be good to hear from all users of the relatively cheap 'Booster Plug' and the 'Rapid Bike Easy' modules.
From what I understand, the 'Booster Plug' fools the ECU into thinking that the outside temperature is lower than it actually is, hence the ECU enrichens the injectors accordingly. It is a very "blunt tool".
Whereas the (slightly tuneable) 'RB Easy' intercepts the Lambda probe signals and modifies them to lower the air/fuel ratio from over 15:1 to slightly under 14:1 across the board, which seems like a slightly better way forward, although still crude compared to a full ECU remap.
No two 'identical' engines are exactly the same, and an individual ECU remap is usually the best option, provided you can find a top-class tuner, or the money for a Coober ECU.
I just keep the revs over 3500 or use Rain Mode in creeping traffic, since my pensioner pockets are not deep. 😉
 

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Discussion Starter · #13 ·
I wouldn't waste my time with a booster plug. I tried it and it didn't solve it.
Thanks for your comments. I'll carry on until the 600 mile service, then see how it goes. Only wish the weather would cooperate, but it'll probably be spring before I can accumulate the 600 miles.
It would be good to hear from all users of the relatively cheap 'Booster Plug' and the 'Rapid Bike Easy' modules.
From what I understand, the 'Booster Plug' fools the ECU into thinking that the outside temperature is lower than it actually is, hence the ECU enrichens the injectors accordingly. It is a very "blunt tool".
Whereas the (slightly tuneable) 'RB Easy' intercepts the Lambda probe signals and modifies them to lower the air/fuel ratio from over 15:1 to slightly under 14:1 across the board, which seems like a slightly better way forward, although still crude compared to a full ECU remap.
No two 'identical' engines are exactly the same, and an individual ECU remap is usually the best option, provided you can find a top-class tuner, or the money for a Coober ECU.
I just keep the revs over 3500 or use Rain Mode in creeping traffic, since my pensioner pockets are not deep. 😉
Thanks for your comment, more stuff to think about.
 

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Like said above, it seems to be an emissions issue. Even on my 2005 ex-Harley-D V-Rod we had that problem. Harley came out with a "Stage 1 FLASH" for the ECM, for "more power". All it did was make the air/fuel ratio a bit richer. Problem cured, bike lugged around at low rpms just fine. Probably won't find that option in the new KTM accessory catalogue. But that is the problem, I believe. Yeah it may void your warranty, so wait a while. For sure an equivalent "flash cure" will be developed by some entrepreneur. I'll be first in line. Running ever-so-slightly richer will actually be better for your bike and will save emissions when your bike doesn't break down and you won't have to buy all those new replacement parts whose manufacture just polluted the air much more than if you had the bike run ever so slightly richer.
Just sayin'...
 

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My new 2020 790 Duke, at less than 300 miles, has one very annoying problem. At low speeds the bike will not proceed smoothly. It jumps ahead then slows, all very suddenly and gets worse if you try to persevere. Its fine at idle or accelerating briskly. Hasn't been to the dealer yet, but in a phone conversation, they suggested its normal for a high performance engine. I don't believe it! Comments please.
Had the same problem with my 790. I have a long gravel driveway and it was very twitchy on the driveway. I would put it in rain mode for the driveway which smoothed things out. My final solution was to get an 890. Totally cured the problem. ;-)
 

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I posted something similar to you. I thought perhaps KTM has an upgraded tune available but I guess not. Not the most inspiring in lower speed turns.
 

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Discussion Starter · #18 ·
Had the same problem with my 790. I have a long gravel driveway and it was very twitchy on the driveway. I would put it in rain mode for the driveway which smoothed things out. My final solution was to get an 890. Totally cured the problem. ;-)
I'm happy for you. Any clue why the 890 doesn't have this problem?
 

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Had the same problem with my 790. I have a long gravel driveway and it was very twitchy on the driveway. I would put it in rain mode for the driveway which smoothed things out. My final solution was to get an 890. Totally cured the problem. ;-)
Can you switch modes while riding?
 
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