Re: KTM Duke 390 - Ownership Reviews and Experiences

Clutch, tires, cables all depends on the ussage Skanda, so it varies from person to person. 19k is a good clutch life and can even be extended till 20k plus if you don't see any hiccups in performance. But since the basket is being replaced, it's advisable to replace the plates together, as once removed from basket, the clutch plate friction material can thin out and cause sudden performance drop, so it's wise to get them replaced as a set along with the basket.

Cheers!
VJ

Re: KTM Duke 390 - Ownership Reviews and Experiences

Sure thing [emoji106]. Will get this done soon.

Re: KTM Duke 390 - Ownership Reviews and Experiences

Thanks for confirming with your mechanic Vijay sir. I was able to go ahead with the engine rebuild at last.


TL;DR
Leak down test on the bench detected leak through crankcase.Piston slightly out of spec. Went ahead with rebuild anyway. OBD scanner detected Fault code P0650-Powertrain [Malfunction Indicator Lamp(ML) Control Circuit] before startup. Engine starts fine when cold and idles normally. Warm engine(70-80°C) will only start with slight throttle input.Brand new throttle cable installed but barely any freeplay(1mm). OBD data video included.

Long version:
Coming to the rebuild, the new head gasket was used and all bolts were torqued to spec with a torque wrench.
Brand new items in the engine :
1. Both Exhaust valves
2. Piston Rings
3. Stator coil
4. Valve Stem seals
5. Engine oil - New cans of Motul 7100 10W50
6. Coolant - Motul Inugel Expert Coolant.
7. NGK iridium spark plug

Did a leak down test of the engine on the bench and found some air escaping from the port where you check for TDC. No air leaking from the valves though. Adding a bit of oil on the piston increased the psi reading and also reduced the air leak. Opened everything again and measured the piston and cylinder. Cylinder was OK but piston was slightly out of spec. Piston diameter was 88.91 at the skirt. [Required 88.931mm...88.949mm]. I've read that new piston rings take time to bed in with the cylinder walls. Could this also be responsible for the leak? Anyways, I've gone ahead with the rebuild. New piston set costs 7500/- and it's not in stock. Might have to change it in the future. Will take a call once I get the valuable expert opinions.

Valve clearance at TDC is as follows(L&R): Intake - 0.10mm & 0.10mm , Exhaust - 0.14mm & 0.17mm

I've used an OBD scanner and torque pro app for data acquisition.
My biggest mistake was not taking any measurements using the OBD scanner before the rebuild. I can't compare the new data with anything now.

Before starting the engine I checked for fault codes and there was one : P0650-Powertrain [Malfunction Indicator Lamp(ML) Control Circuit]. Now I've checked online and the general consensus is that it's a bit difficult to nail the location of this error. It could be the wiring or the check engine lamp or any sensors in the electrical circuit.
Clearing it doesn't make it go away. I'll have to take it to the service centre to sort it out. The check engine lamp works fine though - It flashed an error code when I disconnected the Lambda sensor. Any other place I need to check? Also, can't say if the error was there before or after the rebuild.

Pressed the starter and the engine cranked 4 times and nothing. This happened twice. The third time it came to life instantly and settled to its 1800-2000 rpm idle. No visible smoke from the exhaust. Ran it only for a minute.

Next day ran the engine for a longer duration. Time of day 1:00pm. Ambient air temp - 33°C. I let the bike just idle.
First start impressions: There's still a lot of vibration at idle but reduces at higher rpms. I'd say same as before.
First ride impressions: On the move it feels like a different bike. Vibrations have reduced across the rpm band. Before, I felt something was holding it back but now it feels free. This was just a short ride of 2 km. This Sunday I'll go for a slightly longer ride and do further tests.

Do I need to break-in the engine once again for the piston rings to bed in?

Issues faced: Bike does not start once it has warmed up. A little bit of throttle has to be opened while thumbing the starter. This is audible in the video below at 11:51. This used to never happen before. So something is not right. I installed a new throttle cable and there's barely any freeplay even after adjusting - maybe just 1mm. Could this be the reason?

The video shows OBD data at idle and later during a short ride. I've included chapters for the relevant bits so that one doesn't have to watch the whole video.


O2 sensor oscillation starts at 3:48
Radiator fan comes on (96°C) at 8:10
Coolant temp drops to 90°C at 10:29
First ride after rebuild at 11:51

Here are some data from the OBD scanner.

Intake manifold pressure - Mostly around 9 to 10 psi.
Intake air temp - Max of 57° C. (Is it too high?)
Vacuum - Fluctuates a lot with throttle inputs. Not sure which sensor and at which place this is measured.
Timing advance - 9 to 12° at idle.
Volts - At idle 14 to 14.8 volts. I think the stator coil is doing its job.

Time taken for radiator fan to come on (coolant temp hits 96° C) - 8:11.
Coolant temp to reduce from 96° C to 90° C - 2:18

I was worried about abnormal engine temps so I used an IR thermometer and measured the temp at different points.
This was after revving the bike from 2000 to 5000 rpm for some time. Coolant temp - 100°C.

Engine head(Valvetrain right side) - 92° C
Engine Head(Cylinder area right side) - 85° C
Magneto Cover - 89° C
Clutch cover - 74° C
Exhaust pipe at idle - 240-280° C
Catalytic Converter - 133°C

Experts please tell me if the values are OK or not.

Some before and after pics.

Re: KTM Duke 390 - Ownership Reviews and Experiences

do run it in for a few 100km to break in the new rings.
get the official diag tool connected and checked at the svc for the right info on error codes and fix accordingly.
i am guessing either the tps or idle control stepper motor might be causing the idling issue.
if possible compare the values from the official diag tool, with readings from another 390 of same model yr.

Re: KTM Duke 390 - Ownership Reviews and Experiences

Welcome back Raju. I'll try to be as brief as possible, starting with the valve clearances. They are perfect, nothing to fiddle with. Secondly, I did go through the entire video of the diag, and it seems everything's as it should be. The fan kicks in rightly at 96 degrees and turns off at 90 odd, so your cooling system is working as it's should be. Rest of the readings are sensitive to throttle inputs, as they vary according to the RPM.

Coming to the temperature values, those values are absolutely fine, nothing to worry about. You have more reading on the cylinder surface, even more higher on the exhaust bend pipe and fluctuating readings on the radiator once the fan kicks. With an IR thermo, you can practically see the radiator cooling as the fan kicks in, so again you're perfect on the temperature part.


Rings, like piston do need to bed in, but not as how a piston is bedded in, you can rev the engine freely, hit top whack. Make sure the engine isn't highly revved where the ECM kicks in to cut the RPM. Yes, mild leaks in the piston where the air bled off during the bench test, and your lovely piston skirt test with ratios confirms it. My advice would have been to have replaced the piston along with the rings, considering the bore inner diameter was within spec.


Did you check the compression ratio before and after the rings were installed? Ideal compression ratio should definitely be above 190 psi which would mean 13 to 14 kg/cm2. Near 100 or lesser than 100 psi would mean, we have blowby loss, which is attributed to the worn piston rings and a piston skirt that's values are off by a good margin, which would mean replacement of either the rings or piston with rings, it's usually the latter that's the best course of action.

I'd suggest you to check your compression, that's first, both warm and cold.
Secondly, was your throttle body and injector considered an overhaul for cleaning.

Lovely work as always.

Here's a link for you.



Where I've answered query on a similar line.



Hope it helps!

Keep your observations posted.

Cheers!
VJ

Re: KTM Duke 390 - Ownership Reviews and Experiences

Hi KTM People,

Would anyone be able to share the distance between your motorcycles swing-arm at the point where the axle bolt goes through, also would need the distance between the wheel hubs outer edges, measurement to be taken with the help of the axle bolt, and finally the size of the metal wheel spacer.


Wanted to know if the KTM's rear alloy can be accommodated for the Pulsar 220, also can NS<>KTM alloys be interchanged?


Thanks in advance.


Cheers,
A.P.

Re: KTM Duke 390 - Ownership Reviews and Experiences

Replaced the complete clutch and basket assembly and all the clutch related issue seems to be sorted out. The clutch feels so light and pick up seems to have increased. Previously, slotting the gear to Neutral was painful task and now it's butter smooth.

However, the mild clanking noise in lower rpm when revved bit hard is still there.

The old basket (is this the inner basket?) had slots due to clutch plates, is this normal? New ones were smooth with no slots.

The inner bolt was installed and was locked using threadlocker. I insisted on using a threadlocker but the technician told it was not required. The old oil, though had run only for 800kms, was replaced with new one due to the new clutch.

Re: KTM Duke 390 - Ownership Reviews and Experiences

Finally! The basket slots are nothing to worry about Skanda. It's always recommended to replace the clutch basket along with clutch plates. I hope you've replaced the pressure plate too along with a new clutch bearing. Sometimes, a clutch bearing would seem good, but once in action they start to dance around their axis and make that signature clanking sound. Yes, new engine oil for new is THE WAY to go. Do not use old oil on a new clutch system.

Give it a few days, let the clutch bed in and keep your observations posted.

Cheers!
VJ

Re: KTM Duke 390 - Ownership Reviews and Experiences

Forgot to mention the bearing. Old bearing had bit of wobble and it was replaced. Both clutch and preasure plates were replaced and even the oil filter with a new one.

Re: KTM Duke 390 - Ownership Reviews and Experiences

Very well! Give it few days Skanda, the sound should subside, and keep your observations posted. Take it easy, as the new clutch plates do need to set in well.

Cheers!
VJ

Re: KTM Duke 390 - Ownership Reviews and Experiences

O.T.
I went through the whole discussion, would you mind sharing or DM me detailed the cost of entire clutch basket and assembly cost?

Reason,
I'm in dual minds whether or not switch to a slip and assist clutch, mine being a non slipper clutch model and is about due for a clutch related work in about 5-8K kms.
First I was thinking only changing the plates based on the state of the outer grab plates if there are okay or replace the entire assembly.

Then thought of changing to slipper clutch "while I was at it"
Also from what I've gathered till now, to switch to a slipper clutch assembly in a non-slipper model you need to replace the inner basket aswell. Which adds to extra cost of normal replacement.

I know the benefits and drawbacks of the slipper clutch on a non-slipper clutch model, would like to know if the extra expenses would be well spent.

Re: KTM Duke 390 - Ownership Reviews and Experiences

If I remember correctly, it costed around 4,500Rs.

Re: KTM Duke 390 - Ownership Reviews and Experiences

For every 5K - 8K Kms or before servicing my car, I usually run the engine for couple of mins so that it's hot and then spray 3M Throttle & Intake cleaner through air intake hose by removing air filter. I maintain above 3,500rpm while I continue spraying the liquid through intake. Once sprayed enough, I connect back the air filter and I Revv it to redline or drive hard. Heard that Intake cleaner or small amount of water decarbs the engine and I follow this routinely on my car. It results in smoother ride and less vibrations as soon as this is done. Probably helps in cleaning intake valve as well which is otherwise hard to clean. Car is 98K Kms done and still feels young.

I have done this 3 times on my D390 now and wanted to know the feedback from you guys on how much helpful it is to continue this? And also, if anyone has tried water (very small quantity) to decarb the engine. This is best done before an oil change so that if there is any water which is mixed with oil is replaced with a new oil.

Re: KTM Duke 390 - Ownership Reviews and Experiences

Water in combustion chamber, hmm interesting isn't it. The concept is as simple as it sounds and it works as simple as that. Have you ever seen our moms or hotel tawas being sprayed or dabbled on with hot water and then cleaned off when extremely hot? And this wipes off the grease on the pan surface and makes it spanking clean, along with the steam. This is the same concept being followed here.

When the engine is revved above 2k and after the engine has reached the optimum temperature, which is basically the hot tawa, now when water is sprayed mildly via a spray dispenser or a sprayer intermittently inside the manifold, it does the exact same job, of removing the carbon deposits on the piston head, especially the valves front and back, and steam along with the deposits exit out the exhaust pipe.

If we compare this to our homemade remedy, it's amazingly simple and easy to do.

But, care must be of utmost importance. The manifold shouldn't be sprayed excessive water with too low an engine speed. The RPM must be high and water must be sprayed in mist as opposed to coming out of a tube with full force, this will overload the chamber, hydrolock and boom your engine goes. A mild continuous and intermittent spray is the key here with the engine RPM high.

One can either use water or TB cleaner in the similar fashio. Water is similar to a steam clean which does work if done properly.

Cheers!
VJ

Re: KTM Duke 390 - Ownership Reviews and Experiences

Great explanation! I have done decarb for my car using water spray, as you said in very little quantity and by pulling the throttle cable to keep the rpm high. I made sure to use spray bottle, which helps the water entering the chamber to be almost in mist condition, so that the chances of hydrolock is nill. The results were amazing. I used tiny endoscope camera through sprak plug hole to see before and after effects of decarb which surprised me. Service center charges upwards of 1.5K for decarb sessions which is a simple DIY job. Unfortunately I don't have any pictures saved.

I was curious if anyone has actually tried it on D390? TB cleaner really helped me to keep the rpm stable couple of times and also instantly reduced vibrations. I also had to get the TB cleaned at service center once, to get the idle rpm fixed which was erratic.

I poked the camera through D390 spark plug hole and I already see some carbon deposit on the piston head, though not much which should make one worry. However, my 19.5K run D390 has more carbon deposit than 98K run car which confused me. Due to high compression, the deposit should have been actually low. I can only imaging how is the deposit on intake valve when the piston head itself have some deposit.I recently changed the spark plug to NKG which should help reduce the build up. Due to high compression ratio of D390, is it safe to use water spray Or is it better not to fix which is not broken?