Living With KTM Duke 390 BS-IV (2017)

[sacbiker]

I will only use chain lube from now

This didn't turn out so well. The chain started making sounds after a few days. I applied gear oil again on the chain and it went away.
Incidentally, the fuel efficiency also went up by 7% (27 to 29 kmpl) after this.

I also opened the oil filter to see if it's clogged already after 2000km. A clogged filter will have wavy pleats.
But the oil filter looked fine and it was not even black. It was just browny. It could easily do another 1000 or 2000 km.
Anyhow since I opened it, I replaced it with a new filter and topped it off with 100 ml of oil.

The reason I did this was for an experiment. A mechanic told me that it's the oil filter that gives up in KTM/Bajaj bikes. The fully synthetic oil can last much more but if the oil filter is blocked, the oil pressure will go down.

I did a poll on KTM 390 owners group and most of them change their oil at 4000-5000 km.

I also found another guy with a BS3 390 with 85000km ODO. He also faced oil consumption/disappearance with Motul 7100. Initially he thought it was a damaged engine but he shifted to Castrol Power1 Ultimate and the oil level was stable for the next 5000km.
My friend also recently shifted to Castrol Power1 Ultimate in his Husqvarna 250 and it feels smoother.

 

[sacbiker]

I changed the oil after 2840 km today with Gulf Syntrac 10W50 fully synthetic oil.
The drained oil was about 1.6L
The oil was still brown and not fully black but the oil had surely degraded as the bike was heating up a lot quicker and also the gearshifts were getting harder.
Shell had made claims that they have tested Shell advance ultra oil for extended drain intervals, yet they recommend a drain intervel of 3000 km.
My experience with this oil was average. There is nothing great about it. Gear shifts were also not smooth.
Oil consumption was around 150ml / 1000km.
With the 7100 it was 250ml+ / 1000km.
So definitely there was some improvement in terms of oil consumption.

I also inspected the spark plug and it had a white powder on the tip.

A search in google returned that this usually means the engine is running lean. I once raised this concern with race dynamics previously since this started after adding fuelx lite but they were not so responsive about it. Spark plug is under 7000 km old.
Cleaned it with wd 40 and reinstalled.

 

[sacbiker]

the spark plug and it had a white powder on the tip.

I think it's to do with the heat range of the spark plug. I had thoughts about this while replacing the stock plug with NGK LKAR8AI-9. But, I know several others running this plug without any issues on their 390. KTM even sells this plug as a power part in other countries. The NGK website also shows this to be compatible with the 390.
I also didn't care much since the heat range number (8) of the NGK was similar to Bosch BOSCH VR6NEU (6).

As per the chart from NGK for cross reference, NGK's 8 is same as Bosch's 4. This is too cold. NGK plug should be 2 points lower.

If you use too cool of a spark plug that doesn't heat up to the proper temperature, it won't be able to burn off the carbon deposits, which can cause premature fouling.
I'm planning to replace the NGK with stock Bosch plug at the next service.

 

[sacbiker]

This is the reply from NGK technical support.

 

[sacbiker]

I had to waddle my way through a traffic congestion for about 15 minutes in 1st gear. This caused the infamous 'Low Oil Pressure' error in speedo. I was pretty sure that this is nothing to do with the oil pressure as the level was correct and these pressure sensors never really work unless you are extremely low on oil and the oil pump is running dry. For old bikes like the Yamaha FZ, they used to provide a nut on engine head which we can unscrew to see if oil would gush out. This was the only way to check the oil pressure.
This sensor was last changed about 5 years ago and for a Rs.150 part, it held up really well for so long. I procured the replacement part from a nearby Bajaj service center as it's a shared part in almost all Bajaj bikes like the Dominar and 200 NS.
Part: DK101225, Rs. 148.

This is a normally closed sensor, meaning that electric continuity is closed when the engine is off. When the engine is running, oil will go inside the sensor and push on a spring mechanism, thereby disconnecting the continuity. So, as long as there is enough oil pressure to keep the spring pushed in, the ECU knows that there is sufficient oil pressure. But, over a long period tof time, heat cycles and dirt from the oil can hinder the spring mechanism from working correctly.
As you can see from the photos below, my old sensor had been through a lot of heat cycles and the black moulding which connects the two parts of the sensor had completely disintegrated. When I tried to remove the wire to this sensor, the outer part of the sensor was rotating freely since it was no longer connected to the thread part which bolts on the the engine.

About the actual job itself, it's pretty easy as long as you remove the tank. It can be done without removing the tank as well.
A box spanner is essential to get this done.
I took the bike for a short spin after the work and the error never came back. So, it was a successful DIY.

 

[sacbiker]

Finally replaced the broken indicator.
The part was available in Bajaj but the wire was not long enough for the duke.
There are separate part numbers for left and right indicator but the KTM Spare parts store insisted that both are same.
Cost. Rs 578.

Also replaced the oil cap and washer. Costs Rs. 17.

Oil update.
The Gulf Syntrac oil is amazing. Completed 1000km after the oil change and the bike is running smoothly as the first day of oil change. No false or notchy shifts as noticed with the Shell after 1000km. The level is also stable.

 

[sacbiker]

Someone finally did a Adventure 390 rear shock absorber installation in a Duke 390. It supposedly fits but the adjustable screw is not accessible due to the swing arm as discussed before in this thread.
My refurbished rear shock is shot and leaking after 6 months and 4300km.
So, now it's time to get a new shock. The Duke's shock is readily available at KTM spare parts but the adv 390 one has to be ordered and it will apparently take 2 weeks. Price difference is around Rs1500.
It makes no sense to have the adjustable suspension installed without having the ability to adjust it or to remove the shock every time I need to adjust it, therefore I'm going with the stock part.
Engine oil update
The bike did 2200km with no drop in oil level.
I also did a horn upgrade with Roots windtone horn.
New windtone horns are larger than they used to. So I took older ones from my car and installed in my bike.

Comparison of stock horn with Roots windtone old model and new model.

The only reason why I didn't do a horn upgrade any sooner was that I didn't want to spoil the stock looks of the bike and mount horns on both sides. I installed one horn in the stock horn position and other one in the left crash guard. So, it's kind of discrete.

One day the fuel pump refused to turn on. I removed the tank and found out that the connection inside the tank was loose for some reason. I tightened this and the bike is fine.

 

[sacbiker]

The Duke's shock is readily available at KTM spare parts

Shocks available in KTM spare parts shop turned out to be BS6 model packed in BS4 boxes. BS4 shocks have a plastic mud guard.
They said this(JP122023) is the replacement part now.
I was about to bill and I noticed that there is a shaking sound in it as of something is loose. They confirmed it with another piece and it was also BS6 shock packed in BS4 box with the same shaking sound. They said it's some sort of manufacturing defect and they will send it back to the factory.
They then showed me JY120230.

This one is for the Duke 200 and there were no shaking sounds. They put this side by side with the BS6 390 shock and told me that since the height is same I can use it in 390 as well. They also claimed that the 200 shock is shown as replacement part for the 390 in their catalogue.
I straightaway rejected this.
It will take 1 week for a new BS4/BS6 shock to be available. And 2 weeks + if I want to order the adventure 390 shock. The Duke shock costs somewhere around 5900 and the adv 390 one costs about 7200.
I made an order for the adv 390 shock finally. I am thinking grind off the swing or drill a hole to make it adjustable if it's possible without loosing the structural integrity or I might just install it and forget it.

Adv 390 settings

2024 Duke 390 settings
I also found this, Zedling Suspension which seems to be an Indian manufacturer selling performance suspensions.

 

[sacbiker]

They said it's some sort of manufacturing defect and they will send it back to the factory.

Adventure 390 shock finally came. It costs Rs. 6908.
That is roughly a grand more than the non adjustable type, which is really a good deal.
This one also had the shaking sound. Upon closer inspection, I realised that the sound was not a fault after all. Since these newer suspension comes with fully covered shafts, there is a plastic cover mechanism under the shock to let the dirt and water drain. This cover is free to move up and down the shaft. This was what was making the sound.
Previously KTM's shock absorber shaft was completely exposed to elements.

Old design with exposed shaft.

New design with covering inside the spring on 2024 Duke 390. Interestingly the international variants have an exposed type shock.

The Adventure 390 shock which I installed with a similar inner cover. Notice that the covering is open at the top and water and sand can get trapped inside. There is a door at the bottom to drain this. This is what cause the tik tik sound while shaking it.

Interestingly Yamaha FZ's shock also has this design which is also manufactured by Endurance as is with the case of KTM.
I'm going to set rebound to 10 for reference and then tune it according to my weight by measuring the sag. As I understood, the screw basically controls a valve which restricts the flow of oil inside the shock. The lesser the flow the higher the damping would be and vice versa.

 

[sacbiker]

I installed the new shock absorber today. It was a straight forward job. Remove 2 bolts and instal the new suspension and put the bolts back with some greese.
The preload was kept at default 3 setting.
For rebound, I set it at 13 clicks for now as my regular commute has 1km of non existent coastal roads and I need it to be comfortable.

Rebound adjustment instructions for Adventure 390.
Can't really follow this chart as the Adv 390 weighs about 177kg while the 2017 Duke 390 is about 149kg. (Kerb weight)
With the current setting, there is a sag of 3.5 cm while being on and off the bike. (I weigh 73 kg)

Initial impressions
The bike is gliding over bad patches better than before.
No issues with stability or weight transfer while riding fast. Cornering also feels normal if not a tad bit more confident.

My only concern was if the adjustment screw would rub against the swing arm, but there is more than enough room for the screw.
The test ride was done without rear mud guard and it got all sandy. It's caked with leaked oil from the old shock absorber. Part of it fell flowed over the exhaust canister as well and it's still smoking when hot.

A side by side comparison of Duke 390 and FZ16 shock absorbers. Duke has lesser turns.

 

[sacbiker]

1 X 650 + 3 X 390
I went for a ride today after the adventure 390 shock absorber upgrade. The bike feels a lot more planted. Undulations on the road is filtered better than before and it feels comfortable.
However, I felt that the height has increased a bit. My friend who has ridden my bike before confirmed the same.
After I rebuilt my old shock, the bike used to sit lower. Once I kept the bike on side stand, I could see the dampener expanding and the bike lifting up. That is, once we sit on the bike, it never used to come back up fully. After the new shock absorber installation, it comes up, thus there is a feeling of increased seat height.
Still, I would like to double check this with another 390 and a measuring tape. If there is anyone here with a BS4/BS6 duke 390, kindly share the seat height measured from floor.

 

[deville_56]

Any height difference?

 

[sacbiker]

Any height difference?

This has to be confirmed. I never got a chance to keep both shocks side by side since the rear end of the bike needs to be supported without the shock.
I'm planning to remove it and check again.
Seat heights
FZ16 790mm
Bs3 390 800mm
Bs3 duke 200 810mm
2017 duke 250 822mm
2017 duke 390 830mm
2024 duke 390 820mm
2018 rc390 820mm

 

[sacbiker]

I couldn't really sleep well yesterday because of this. As soon as I reached back from work today, I removed the shock absorber and kept a wood piece in place to support the bike.

And then I took multiple photos of both shocks absorbers side by side for comparison.

Both look virtually the same.
Maybe the Adventure 390 shock is 1mm higher?
I have set the rebound to 12 clicks.

 

[sacbiker]

12 clicks of rebound felt a little stiff. Removed the shock and set it to 13 as before and I can really feel the difference.
The amaron battery started acting weak after 3 years. I pried open the top cover which was kind of glued to the battery, and found out the battery was literally dry and had no distilled water inside.
It's told that it's a maintenance free battery, but as far as chemistry goes, a battery needs an electrolyte to store charge. I filled it up with battery water, closed the cover and let it charge overnight.
It's been few weeks since that and the battery is going strong.
Tank cover was giving annoying vibrations. Fixed with with some 3M double side tape.
There is a puff of white smoke when the bike is cold started and slightly revved. No smoke whatsoever after the engine is hot.
This means that the valve stem seals are leaking oil down the combustion chamber overnight when the bike is parked. Valve stem seals used in the 390 are the same seals which are used in all Bajaj bikes, I doubt whether they can last half as long considering the heat procured by 390.
I'm looking forward to get them replaced at the service center. Might as well do a full top end rebuild by replacing valves, springs and shims as the valves have to be seated after the procedure.
I sort of enquired and they told me it's be in the ballpark of 5000-6000 to get it done, which seems reasonable. I'm still considering any reputed FNG if possible since I don't want anyone to message up the whole engine and the ktm service center here has a habit of wanting to replace the cylinder head for no reason. I might even say F it and just do it myself if I'm in the right mood.
The Ceat Zoom Rad rear tire is worn down to the thread life indicator after running about 8000 km.
The TFT speedometer somehow got some water inside the LCD and it's slowly fading away. It needs a fix sooner or later. I think it can be fixed.
I had replaced the speak plug to the stock one to see if there is any difference in white compund formation. After running about 2000km, there was this white compund of the stock spark plug as well, so I swapped it back to the iridium one. I think this is due to the oil burn from bad valve seals.
Interestingly, after swapping back to the IR plug, mileage increased slightly.