KTM Duke 390 Forum banner
1 - 19 of 19 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter · #1 ·
Got myself a brand new 2016 Duke 390 a couple of weeks ago after many weeks of internet research and completely falling head over heels in love with it. its my second bike ever and my first brand new bike. booked in for its first service next week and already have the DNA filter ready to install after. New Ergo seat and handguards coming soon as well!
 

Attachments

·
Registered
Joined
·
35 Posts
Nice one!

Be a bit careful adding any feeling mods without first checking whether you need a piggyback ECU thingy, as these bikes are notoriously lean from the factory, so you could damage your engine. Check out the 15 minute ECU reset threads too, as is might be enough.

I'm not techie enough to advise.

Ride safe!
 

·
Registered
Joined
·
2,194 Posts
Welcome BES, and congrats on your bike! The advice you just received from the Duke of Dork illustrates how valuable this forum can be to both new and experienced Duke owners. He is spot-on with his recommendation.

The 390's marketed in places such as the EU, North America and Australia are delivered with a very lean air/fuel ratio (AFR) mapped into their ECU. This is in order to pass emissions testing in their respective countries. This lean mapping results in a certain amount of engine surging, especially at low throttle settings, and is one reason the engine tends to run quite hot.

To preserve your engine's health, you really do not want to do anything to aggravate this already borderline-dangerously lean condition that exists using the stock airbox, air filter and exhaust. Any modification to one or more of these components will alter the bike's AFR by flowing more air, and will lean out the AFR even further, putting you into the danger zone. Overly-lean running could hole a piston, among a host of potentially unpleasant consequences.

Bottom line: If you want to modify your airbox, air filter or exhaust (as many owners do), then you should perform these mods in conjunction with fitting a fuel controller that can adjust the engine's AFR back to a safe level. But until you have installed a fuel controller, don't put your bike at risk by modding any of these components. In your present situation, this means holding off on fitting your DNA filter (which flows considerably more air than the stocker) until you have a controller to compensate for this change. No problem with the DNA filter if your bike is prepared to accept it, but wait until you have a controller.

Enjoy your Duke and ride safe!
 

·
Registered
Joined
·
102 Posts
Congratulations. Welcome!
 

·
Registered
Joined
·
27 Posts
Welcome BES, and congrats on your bike! The advice you just received from the Duke of Dork illustrates how valuable this forum can be to both new and experienced Duke owners. He is spot-on with his recommendation.

The 390's marketed in places such as the EU, North America and Australia are delivered with a very lean air/fuel ratio (AFR) mapped into their ECU. This is in order to pass emissions testing in their respective countries. This lean mapping results in a certain amount of engine surging, especially at low throttle settings, and is one reason the engine tends to run quite hot.

To preserve your engine's health, you really do not want to do anything to aggravate this already borderline-dangerously lean condition that exists using the stock airbox, air filter and exhaust. Any modification to one or more of these components will alter the bike's AFR by flowing more air, and will lean out the AFR even further, putting you into the danger zone. Overly-lean running could hole a piston, among a host of potentially unpleasant consequences.

Bottom line: If you want to modify your airbox, air filter or exhaust (as many owners do), then you should perform these mods in conjunction with fitting a fuel controller that can adjust the engine's AFR back to a safe level. But until you have installed a fuel controller, don't put your bike at risk by modding any of these components. In your present situation, this means holding off on fitting your DNA filter (which flows considerably more air than the stocker) until you have a controller to compensate for this change. No problem with the DNA filter if your bike is prepared to accept it, but wait until you have a controller.

Enjoy your Duke and ride safe!

Are you saying a 15 minute reset wont adjust for the performance air filter?
Ive been running mine since last August and Ive had no issues, but its been cold.
 

·
Registered
Joined
·
2,194 Posts
First posted by Mejetski2000 (Quote):

Adaptive ECU function is a beautiful thing which can adapt to MINOR changes in fuel quality, air temp and density and so on but think of it as a cane, not a foundation, particularly if engine operating parameters are being modified substantially. Since this bike suffers from acute lean fueling from the factory having a base map with enriched fueling such as the Akrapovic software should be an initial tuning approach and build from that with a piggyback ECU or tuning device IF needed.
Pete (End quote)

How exactly the 15-minute reset function works, the extent and permanence of resulting adaptive changes, and what, if any, benefits are to be gained from this procedure, are something of a mystery. Some Duke owners have tried it with success to cure issues such as stalling. Others have tried it with no improvement, or a temporary improvement with subsequent regression to the previous issue. There seems to be no clear answer as to whether it is an effective palliative for engine fuelling problems, or just a false hope. I cannot elucidate the issue, but the above quote from very knowledgable Duke owner Mejetski2000 seems to me the best analysis. He believes the procedure can make "MINOR" learned adjustments to the AFR. Whether such minor adjustments are sufficient to compensate for the leaning influence of a performance filter is anyone's guess. Between the Akrapovic map, the 15-minute reset and a fuel controller/piggyback ECU, the latter is by far the safest option, IMO, if an owner wishes to alter the bike's intake or exhaust from stock configuration.
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #9 ·
Nice one!

Be a bit careful adding any feeling mods without first checking whether you need a piggyback ECU thingy, as these bikes are notoriously lean from the factory, so you could damage your engine. Check out the 15 minute ECU reset threads too, as is might be enough.

I'm not techie enough to advise.

Ride safe!
Welcome BES, and congrats on your bike! The advice you just received from the Duke of Dork illustrates how valuable this forum can be to both new and experienced Duke owners. He is spot-on with his recommendation.

The 390's marketed in places such as the EU, North America and Australia are delivered with a very lean air/fuel ratio (AFR) mapped into their ECU. This is in order to pass emissions testing in their respective countries. This lean mapping results in a certain amount of engine surging, especially at low throttle settings, and is one reason the engine tends to run quite hot.

To preserve your engine's health, you really do not want to do anything to aggravate this already borderline-dangerously lean condition that exists using the stock airbox, air filter and exhaust. Any modification to one or more of these components will alter the bike's AFR by flowing more air, and will lean out the AFR even further, putting you into the danger zone. Overly-lean running could hole a piston, among a host of potentially unpleasant consequences.

Bottom line: If you want to modify your airbox, air filter or exhaust (as many owners do), then you should perform these mods in conjunction with fitting a fuel controller that can adjust the engine's AFR back to a safe level. But until you have installed a fuel controller, don't put your bike at risk by modding any of these components. In your present situation, this means holding off on fitting your DNA filter (which flows considerably more air than the stocker) until you have a controller to compensate for this change. No problem with the DNA filter if your bike is prepared to accept it, but wait until you have a controller.

Enjoy your Duke and ride safe!
I was under the impression from Maljohann's mod thread that the DNA filter was fine when he put it on his bike without other mods?
 

·
Registered
Joined
·
2,194 Posts
MalJohann's bike is equipped with a Powertronics fuel controller.
 

·
Registered
Joined
·
23 Posts
First posted by Mejetski2000 (Quote):

Adaptive ECU function is a beautiful thing which can adapt to MINOR changes in fuel quality, air temp and density and so on but think of it as a cane, not a foundation, particularly if engine operating parameters are being modified substantially. Since this bike suffers from acute lean fueling from the factory having a base map with enriched fueling such as the Akrapovic software should be an initial tuning approach and build from that with a piggyback ECU or tuning device IF needed.
Pete (End quote)

How exactly the 15-minute reset function works, the extent and permanence of resulting adaptive changes, and what, if any, benefits are to be gained from this procedure, are something of a mystery. Some Duke owners have tried it with success to cure issues such as stalling. Others have tried it with no improvement, or a temporary improvement with subsequent regression to the previous issue. There seems to be no clear answer as to whether it is an effective palliative for engine fuelling problems, or just a false hope. I cannot elucidate the issue, but the above quote from very knowledgable Duke owner Mejetski2000 seems to me the best analysis. He believes the procedure can make "MINOR" learned adjustments to the AFR. Whether such minor adjustments are sufficient to compensate for the leaning influence of a performance filter is anyone's guess. Between the Akrapovic map, the 15-minute reset and a fuel controller/piggyback ECU, the latter is by far the safest option, IMO, if an owner wishes to alter the bike's intake or exhaust from stock configuration.
Sounds like you know your stuff. Question: I have a 2021 D390 with 1500 miles. I'm running the cat and pre-muffler but no muffler. I've added a K&N filter and drilled (2) 3/4" holes in the bottom half of the airbox. Bike runs strong, cool, and only minimal popping on down-shifts. How do I know if I'm running lean? I don't really want to invest in a controller as it has been recommended to not modify the exhaust system in any way. Much thanks!
 

·
Registered
Joined
·
661 Posts
Sounds like you know your stuff. Question: I have a 2021 D390 with 1500 miles. I'm running the cat and pre-muffler but no muffler. I've added a K&N filter and drilled (2) 3/4" holes in the bottom half of the airbox. Bike runs strong, cool, and only minimal popping on down-shifts. How do I know if I'm running lean? I don't really want to invest in a controller as it has been recommended to not modify the exhaust system in any way. Much thanks!
Holy thread revival! One way you can tell is based on how your spark plug looks. After you get some miles on it with the new setup have a look at your spark plug and compare it to a spark plug chart on line. If it is white on the strap, you are running lean. You want to see a brownish color.
 

·
Registered
Joined
·
747 Posts
The only problem with the spark plug approach is that it doesn’t take long to damage the engine from running lean. If you’ve removed the slip on and drilled holes in the airbox you should be strongly considering adding a fuel controller. If you aren’t sure if you need one then you should be considering a fuel controller. Piggyback ECUs are cheaper than engine rebuilds.

You should also be very careful about what you read in a thread about Euro3 gen 1 bikes when you have a Euro5 bike with different mapping, ride by wire, airbox and exhaust.
 

·
Registered
Joined
·
23 Posts
The only problem with the spark plug approach is that it doesn’t take long to damage the engine from running lean. If you’ve removed the slip on and drilled holes in the airbox you should be strongly considering adding a fuel controller. If you aren’t sure if you need one then you should be considering a fuel controller. Piggyback ECUs are cheaper than engine rebuilds.

You should also be very careful about what you read in a thread about Euro3 gen 1 bikes when you have a Euro5 bike with different mapping, ride by wire, airbox and exhaust.
Good points! Thank you. Which controller do you recommend?
 

·
Registered
Joined
·
747 Posts
Good points! Thank you. Which controller do you recommend?
I did a video on this once. The answer depends on what you want to do with the bike. Cheaper to buy a better one if you intend to do more modifications later. But currently, as with all new models, it takes time for the aftermarket to react. I hear boosterplug don’t intend to make one but no huge loss there. Coober I believe do one but you clearly aren’t worried about the warranty so your options are probably wider.
 

·
Registered
Joined
·
661 Posts
The only problem with the spark plug approach is that it doesn’t take long to damage the engine from running lean. If you’ve removed the slip on and drilled holes in the airbox you should be strongly considering adding a fuel controller. If you aren’t sure if you need one then you should be considering a fuel controller. Piggyback ECUs are cheaper than engine rebuilds.

You should also be very careful about what you read in a thread about Euro3 gen 1 bikes when you have a Euro5 bike with different mapping, ride by wire, airbox and exhaust.
I completely agree. My suggestion was based on his initial response of not wanting a fuel computer. The answer would be to get a fuel control for sure.
 

·
Registered
Joined
·
23 Posts
I completely agree. My suggestion was based on his initial response of not wanting a fuel computer. The answer would be to get a fuel control for sure.
You were right. Pulled the plug and it was white rather than golden brown. I put the stock filter back in and plugged the holes until I decide on a controller 😊
 

·
Super Moderator
Joined
·
1,811 Posts
Me 2 cents, if you opt for a Rapid Bike EVO, the advantage is that if/when you sell your Duke without the piggyback (restoring the filter and exhaust to OEM standards) you most likely can use this piggyback on your new ride.
You will obviously need a new loom (from RBEVO) and a reflash but the unit itself can be moved to the new bike.
I think (strongly) that this is possible with a PowerTRONIC as well but you'll need to verify this.
Coober and the Booster Plug are brand/model/year dependent so no fun here.
Check with Power Commander V if their units can be swapped to another bike, no idea.
Athena and some others are also brand/model/year dempendent.
My choice in your case would be the EVO from Dimsport.
 
1 - 19 of 19 Posts
Top