[basuroy]

Originally Posted by man_of_steel

Did you reinflate the tire after riding it for quite a bit?



Dont worry, thats the cat-con cooling down.

I re-inflated them within 40/50km of checking the pressure , riding in between involved good roads , easy on bumpers or bad sections .

At first I assumed it to be a one off so rode for another 40/50km duration before checking an hour back and it is same again :O

Odo reads 150km right now .

[sharanvenu]

With the erratically high compression ratio the D390 utilizes, output is guaranteed in terms of BHP. Heat is just a bye product :-)
What the engineers tried to do here is to just control the heat of the engine enough that it doesn't destroy the engine itself. I am yet to see a summer on my D390, but I assume that I will not see the overheating warning on my Duke.
With the bare bones approach, the chosen radiator just prevents the bike from overheating.
While doing 200+ kms non stop, my duke's temp gauge hovers at 60% to 75%. And the moment you stop or slow down, the gauge rises to above 80% And the moment you put your feet down, the fan starts to humm... I have tried waiting for ~ 2 min, but the fan would still be spinning in full blast. So gave up trying to wait till the bike cools off.
And the most crucial thing to be noted is that the 390 was never intended to be a city commuter and that design philosophy is affecting all of us while navigating through the city.
What I think is, the D390 is designed to heat up and we all will have to live with that.
And its Otto Cycle which governs the gasoline engine, not Carnot. Remember, CAR...NOT. It can never power a car engine. Its a hypothetical engine.:-)

[ebonho]

Originally Posted by shan_ned

Since this is a genuine concern, is there a way or channel through which we can get this clarified from KTM ?

What do you expect to hear?

[man_of_steel]

Originally Posted by basuroy

I re-inflated them within 40/50km of checking the pressure , riding in between involved good roads , easy on bumpers or bad sections .

It is always advisable to check the tire pressure once the tire is cold. If you fill up 35psi when the tire is hot, the pressure will definitely be lower when you check it once it is cold.

BTW. 35psi for rear is a bit too much.

[unni.ak]

I've been reading the 390 thread for a while now and plan to pick one up in the near future. On the radiator topic, if you shut the engine down without the fan stopping, that means atleast for the next few minutes, the engine temperatures are going to rise. Hmm is this what leads to oil leak at the engine head, with the seal unable to take the heat generated?

Ideally the radiator + fan combo should be able to cool down the engine enough so that the fan can shut off. If you keep it at idle, the fan might come on after a while depending on ambient temperature, load on engine etc. But then, thats ideal!

[the VTEC guy]

When the Duke 390 was launched last year there was one concern people raised on possibly spending close to 20 k on replacement tires as they are soft compound. I know many folks who have moved on to Michelin or others when it was time to replace the tires. Wanted to know if there is anybody on forum who has changed the Metzlers with new set of Metzlers? What is the actual cost today since its more than 15+ months since the Duke is launched? Is the wear of tires really worry some?
For me the tires are still looking strong. Its close to 1 year and 6500 kms and feel they will last atleast 5k more. And no I am not sedate while driving my Duke when I find open roads.

[basuroy]

Originally Posted by man_of_steel

It is always advisable to check the tire pressure once the tire is cold. If you fill up 35psi when the tire is hot, the pressure will definitely be lower when you check it once it is cold.

BTW. 35psi for rear is a bit too much.

Tire pressure were checked all 3 times after running for 10km at least , i took due care to do that today morning as well in the manner of a short joy ride .

Why do you feel the pressure is dropping by margins of 5/7 psi within 50km of running at sedate pace , there is no puncture either and as it stands , a pressure drop of that magnitude renders the bike useless for anything more than 20km round trips .

35psi was done by the pressure chap , i just let it be . Today I requested it to be brought down to 30 though

[shan_ned]

Originally Posted by ebonho

What do you expect to hear?

I agree, we will get nothing.
In the best case, we may get a simple answer from them saying that the concern is unfounded. Being an optimistic guy and if the issue is genuine, KTM may take it as a feedback... Of course, it may not happen as well unless a good number of customers raise their concern enough to be heard by them.

[ebonho]

Originally Posted by basuroy

35psi was done by the pressure chap , i just let it be . Today I requested it to be brought down to 30 though

For solo riding, its 25 for the front and 29 (28.5 per the manual) for the rear.

[sridhu]

Originally Posted by ebonho

For solo riding, its 25 for the front and 29 (28.5 per the manual) for the rear.

I 'round it' off to 26 & 30 since I ride about 4km to fill petrol & air

[sandeepmohan]

Originally Posted by sharanvenu

What I think is, the D390 is designed to heat up and we all will have to live with that.

Well; I don't know of any liquid cooled motorcycle that runs cool in our conditions. In the case of the Duke, there is next to nothing to isolate the rider from engine heat.

I am really curious to know how the RC series hold up in places where temperatures go well above 40 degrees centigrade. In my city, summers are not anywhere as bad as what some other regions experience and the Duke still runs super hot.

Originally Posted by unni.ak

On the radiator topic, if you shut the engine down without the fan stopping, that means atleast for the next few minutes, the engine temperatures are going to rise.

I've had the Hot Engine warning light up because of insufficient engine shut down time (read traffic light) and re cranking. The lamp lit up as soon as I re cranked and switched off as soon as the radiator fan fired up. Post this experience, I have never shut down the engine even at a 120sec traffic light. Keeping the engine running sure burns fuel but I've also noticed that I am a good two bars down in the first segment which is safe enough.

Originally Posted by unni.ak

Hmm is this what leads to oil leak at the engine head, with the seal unable to take the heat generated?

In most cases, Yes. The quality of the beading is important as well.

[shan_ned]

Originally Posted by sandeepmohan

I've had the Hot Engine warning light up because of insufficient engine shut down time (read traffic light) and re cranking. The lamp lit up as soon as I re cranked and switched off as soon as the radiator fan fired up. Post this experience, I have never shut down the engine even at a 120sec traffic light. Keeping the engine running sure burns fuel but I've also noticed that I am a good two bars down in the first segment which is safe enough.
.

It is okay not to switch off the engine at the traffic signal. How do you operate on reaching the destination? I mean - Do you wait for period before your switch-off the engine? If so, how long do you wait? The thing is it becoming like handling a turbocharged vehicles

I am more concerned about switching off the engine suddenly which in turn leads to some damage.

[the VTEC guy]

Originally Posted by ebonho

Lots of engineers here. I'm just a doctor. Who rides.

Call me paranoid, but if a bike heats up to just shy of its max threshold limit, and then stays there under load (running hard), but then refuses to budge even a bar even after more than 10-15 minutes of idling (no load), ..
Not so on the 390? Why? Whats different? Whats special?

Originally Posted by man_of_steel

If you are talking about the Indian bikes, almost all others (even 200) has good cooling characterisics. And I think CBR250R has one of the best in business.

Originally Posted by sharanvenu

With the erratically high compression ratio the D390 utilizes, output is guaranteed in terms of BHP. Heat is just a bye product :-)

Originally Posted by sandeepmohan

Well; I don't know of any liquid cooled motorcycle that runs cool in our conditions. In the case of the Duke, there is next to nothing to isolate the rider from engine heat.
I am really curious to know how the RC series hold up in places where temperatures go well above 40 degrees centigrade. In my city, summers are not anywhere as bad as what some other regions experience and the Duke still runs super hot.

It would be interesting to compare the actual surface temperature of the engine for the liquid cooled bikes available in India. I think every manufacturer will target the ambient working temperature. For many bikes (where ever available) the temperature meter does not show actual temperature. It is mostly indicative(%) temperature.
It could be that the actual surface temperature of the CBR cyclinder head may be same as that of Duke's. Say for e.g. 90 deg C. However the fairing, direction of cooling airflow etc makes one feel duke is hot in operation. Mainly becasue of the hot air flowing towards your legs.

[man_of_steel]

Originally Posted by shan_ned

I mean - Do you wait for period before your switch-off the engine? If so, how long do you wait?

I usually idle the bike for 30 secs before switching it off.

The thing is it becoming like handling a turbocharged vehicles

Comparing it with a superbike will be better in this comparison. The 390 can be the opening paragraph of how to live with a superbike in India book.

Its the same case with superbikes. In the cross-plane R1 (2010 IIRC) I have once tried, there is a realtime temperature readout instead of the traditional bar-stuff. The engine warms up and idles at around 60-65deg C. And once after riding it in moderate traffic, my friend switched it off the moment we came to a halt. We decided to move after a couple of minutes, and when he switched the ignition on, the temperature was at 107deg C and the engine plainly refused to start with MIL on and the fan continuously running. And we had to wait for a whole 5 or 10 minutes until it came down to 104 or 102 deg C before he could crank it!

[sandeepmohan]

Originally Posted by shan_ned

How do you operate on reaching the destination?

I don't wait at all. Conditions are such that when I reach my house, the fan isn't spinning, I have not been riding fast or keeping high engine speeds, I am still down by two bars on the first segment and I know for sure I am not re cranking for a while. Yes; the temperature will rise after engine shut down but I've noticed that letting the radiator fan kick in does not improve the situation. Once the fan comes on, it never goes off on a very hot engine.

The engine shut down process is situation based for me. If I am belting down a highway and decide to do a sudden pit stop, I idle the engine a bit. If its a planned stop, I don't.

I find the trigger for the radiator fan a little too aggressive. You stop at a long traffic light. I keep the engine idling. Fan starts up and keeps running. Traffic light turns green, I start moving at a speed of no more than 20-30kmph considering I am in the thick of traffic inching slowly to cross the signal. In this short time I have started to move, the radiator fan turns off, possibly instruction from the ecu that the bike has started moving and natural air flow can take care of cooling. Not good. Its taking place too soon. Temperature starts rising, fan restarts.