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.