KTM Duke 390 Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
Midwest, US

Bought a new 390, have put few hundred miles on it. Already changed the oil and have performed some other maintenance / services.

The coolant is just a tad below the min line in the overflow tank, and hasn't receded further (so I don't think its a leak, just the dealer didn't quite top it off at assembly, along with the many other things they didn't quite finish during ass'y). I've been mostly riding within a few-ish miles of town and not super hard, so I haven't been too worried about the coolant reservoir being a tad low. But I have a longer, more rural trip coming up. I ordered the recommended M3.0, but the shipment was delayed and won't be here in time, so I'm looking for alternatives.

It appears that the M3.0 is purple, while the coolant the dealer put in is green. I'm assuming it at least meets the spec in the manual:

51694


Which means I'm assuming its something like this:

https://www.autozone.com/antifreeze-radiator-additives-and-windshield-wash-fluid/antifreeze/peak-original-equipment-technology-asian-vehicles-green-antifreeze-and-coolant/720592_0_0

I'd ask the dealer what they put in, but they are an absolute pain to communicate with and are a couple hundred miles away. Note that this dealer is also and primarily a Yamaha, Kawasaki, Honda, and Suzuki dealer, so it wouldn't surprise me if they use 'Asian' coolant across the board where it meets the spec.

So the questions are:
  • Think I'd be safe to top off with the linked coolant?
  • If not, how should I top this off instead?
I'd prefer to avoid doing a full flush in my current location, so there must be some safe way to top it off.

I'm relatively mechanically inclined, but have always worked on cars and have never really had to venture into comparing coolant specs, so this is kinda new for me. The only thing I'm really worried about is potentially mixing ethylene glycol and propylene glycol? They should both be OAT, though.
 

·
Registered
Joined
·
135 Posts
Interesting. For the record, ethyl glycol and propylene glycol can be mixed, and are often combined in an engine coolant because propylene gycol will not boil until 369 degrees F at 15 psi pressurization. That very fact means the coolant stays attached to/in contact with the hot engine metal, instead of bubbling and reducing localized heat dissipation. The other difference between them, though, is ethyl glycol is an antifreeze, propylene glycol freezes too easily. If it's gonna be hot anyway, a bit of propylene glycol is gonna enhance cooling. The other option, of course, is to simply add a child's tea cup full of distilled water to that tiny reserve tank.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #3
Interesting. For the record, ethyl glycol and propylene glycol can be mixed, and are often combined in an engine coolant because propylene gycol will not boil until 369 degrees F at 15 psi pressurization. That very fact means the coolant stays attached to/in contact with the hot engine metal, instead of bubbling and reducing localized heat dissipation. The other difference between them, though, is ethyl glycol is an antifreeze, propylene glycol freezes too easily. If it's gonna be hot anyway, a bit of propylene glycol is gonna enhance cooling. The other option, of course, is to simply add a child's tea cup full of distilled water to that tiny reserve tank.
Thanks for the info! In my admittedly cursory searching a few sites warned against it, perhaps because they didn’t want to expand on the details or because you may forget what ratios you have and end up with insufficient antifreeze ability. And yeah, distilled water - I think I’ll go that route and add a tad. I think I may flush it later in the year just so I know exactly what’s in there, so the water should tide me over til then.
This kinda makes me want to research coolants more, but there’s already too much info bouncing around up there haha. Maybe when I get around to flushing it.
 

·
Super Moderator
Joined
·
1,076 Posts
On the coolant, if the level hasn't reduced during the 161 km's you mentioned I would leave it be.
As long as there is coolant in the expansion vessel (and not dropping) you are good to go.
If you still want to bring it up to the level line, I would (in summer) just add 10 - 20 cl of distilled water.
 

·
Registered
Joined
·
11 Posts
Hi
Just use normal or high quality coolant, recommend premix coolant 40% or 50% eyhylene glycol.
Capacity about 1.2L including compensating tank, operating procedures the same to vehicle.
The color is just a dye for inspection and identification don't worry about the color, factory coolant is the cheapest.
Note:
1. The coolant ingredients do not contain phosphate and silicate, because this is an aluminum alloy engine.
2. The coolant disposal in accordance with local regulations. Coolant is a toxic chemicals.
 

·
Registered
Joined
·
20 Posts
FWIW my 2019 was about at that same level for the first 700 miles without any issue. I got the recommended KTM coolant in case it started dropping, but since the level stayed constant I didn't add any. I wanted to wait until I spoke with the KTM mechanic on my first service to make sure the expansion tank didn't need that much space. They said it didn't and they topped it up so it's just under the top line, where it's remained for the last 900 miles. I'm not a good enough mechanic to recommend anything other than the factory recommended coolant, but if I needed something in a pinch I'd just add distilled water as long as you don't need to worry about freezing temperatures. I'd then flush and refill with factory coolant at my next opportunity.
 
1 - 6 of 6 Posts
Top