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Hi I just would like to know what japanese brand is a good replacement for the stock radiator fan on the duke 390. Can you suggest the model also and its specs. I might convert to dual fan.

Cheers
 

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Hi Kenny go to SPAL USA websight , the OE D390 fan is a sucking unit.
If you run 2 sucking fans you can roast both knees... just saying lol
Chris
 

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This is the SPAL fan you need for direct, plug-in replacement of the OE fan. Pete found this source that is less expensive than SPAL itself (Thanks Pete!)
You can order the cheapest option - without connector - because you will need to attach the connector from the bike.


A1 Electric Online Store: Spal 30103011 5.2" Fan (pull)
 

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Psst, found on Amazon with FREE shipping.....

Don't buy them all please

Pete
Hey Pete, did you end up doing the change over? Engine Ice and the fan? I have a cpl of questions. I've read and re-read that the fan's on our bikes are not your typical push or pull type. I've read that the fan functions as a pull fan most of the time, however, when at stand-still or going very low speeds it actually pushes the air forward instead of pulling it in. Apparently they did this to solve the heat coming off of the engine on to the riders legs (Are fan's even able to do both?) i thought that the blades on the fan were designed in such a way that it can only push/pull air in one direction. If so, would the SPAL be able to do both? push/pull?

Also, for the Engine Ice. Is it as simple as removing the drain screw, opening up the radiator cap, loosening the bleeder screw and emptying out the coolant and re-filling it with Engine Ice? I don't think i'd need to do the vinegar and such as there shouldn't be any rust as the bike is still brand new. i will flush it with just distilled water first and then add EI. Do i need to be extra careful about anything? Thanks much
 

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For our elucidation, could you please reference the literature in which you have read about this purported pull/push arrangement for the fan? Such a thing would be, at the very least, bizarre. Given that the radiator and fan are not over-generously sized for the task of cooling the hot-running motor, it would make no sense to use a pusher orientation for the fan - pusher fans are generally known to be no more than 80% as efficient as pullers. From feeling hot air on my leg at a stoplight I can verify that the fan pulls only. The SPAL fan I plan to install will be a puller only. This is the most efficient arrangement. The reports of a pull/push fan orientation on the 390 Duke, I believe, are the motorcycling equivalent of old wives tales. I have been wrong before, but this seems to me utter nonsense, poppycock.

Pete will be the team leader on this once he has accomplished the original-coolant-to-Engine-Ice conversion and can then guide us. But I would suggest that you mix distilled water with vinegar to flush your engine. The coolant system flush will be more complete and effective using the recommended method. What say you Pete?
 

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Hey Guys, my fan shipped today from Amazon. While it's possible to reverse the rotation of an electric motor and fan doing so for a motorcycle it isn't anything I've ever run across in close to 40 years worth of exposure and wrenching. I've owned some pretty sophisticated bikes and none of them had such a feature (I think BMW or Ducati would have gone to style if there were any practical reason to do so). Coolant replacement is very straight forward as outlined in the service manual. Open the drain screw in water pump, crack the radiator and reservoir caps and drain system completely. I'll be pulling the thermostat hose as well to empty as much as possible. I'll also refill with distilled water ONLY and run until engine gets hot. Let cool, drain and re-fill with Ice. You want to get as much glycol out as possible and weaken whatever doesn't come out.

Follow the manual's procedure for filling system and bleeding. I'd fill to the top line of the tank since it will likely settle a bit lower after a few heat cycles. Monitor level for a few days just to make sure Murphy sits this one out : )

Hope this helps...

Almost forgot, Will's suggestion regarding a vinegar flush would be most appropriate if we're putting regular glycol-based coolant back in but I think I'd stick with just straight distilled water to reduce acidity levels as much as possible. When GM switched over to Dexcool we discovered the hard way that it's anti-corrosive properties weren't anywhere near as good as conventional anti-freeze. While EI has better heat transference I intend to monitor residue levels in the radiator to make sure it doesn't allow corrosion once it's been in use for a while.

Pete
 

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hey Will,
here's one of the links:
KTM 390 Duke: First service update | Motovore

second paragraph and i've also read this elsewhere multiple times while researching this bike. Personally to me, it also sounds like a "old wive's tale" but something i want to be sure of before going and changing my fan.

Can you give me your reasoning for adding the vinegar? not that i'm totally opposed to it, just wondering the need for it in a new bike.
 

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My 2015 390 Duke pushes air forward at idle. Just put your hand in front of the radiator with the fan running at a stop. Since this would not work at speed I believe the fan must run both ways. I thought I read it as change from early 390 Duke due to complaints of felt heat in heavy traffic. I have not been able to find the article. I have read of other bikes with the same arrangement. Could this be helping the stock blade to come loose?
 

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I'm not the first guy on this forum to use the Spal fan as a replacement for the OE unit. He's in Australia IIRC and hasn't had any issues since doing the conversion, quite the contrary in fact. Frankly I don't give a d**n which way it rotates but I DO want a unit that won't come apart and has better airflow than OE. Given the shoddy performance (and longevity) of the OE piece I can't think of one reason why NOT to replace the fan.

Pete
 

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Point being if the factory wiring runs the fan both directions it could post a problem for a threaded or screw on fan. What retains the Spal blade?
 

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Press fit. The OE may possibly be manufactured in India, haven't and probably won't see any country of origin label on it. If so I'm willing to bet that the Italian made product will be of better quality, since Spal gives it a 3 yr warranty and the OE only has a one year for the US market. It's a well established fact in the industry that OE components aren't always selected for better quality but for a better price point for the manufacturer. I'm installing what I truly believe to be a premium component as compared to a mass-produced unit.

Pete
 

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Glad this is coming about, while its never overheated in 1700 miles I don't like the temp gauge staying so high at all times.
Hank, maybe this will make you feel better. When I measured the cylinder and radiator temps with a Snap-On infrared thermometer at fan actuation temp the radiator temp was only 205 degrees and the exterior cylinder temp was about 185 degrees. The gauge was at normal temp, 2 bars below the break. If it bugs you, try installing some Engine Ice.

Pete;)
 

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Hank, maybe this will make you feel better. When I measured the cylinder and radiator temps with a Snap-On infrared thermometer at fan actuation temp the radiator temp was only 205 degrees and the exterior cylinder temp was about 185 degrees. The gauge was at normal temp, 2 bars below the break. If it bugs you, try installing some Engine Ice.

Pete;)
That may be my 1st step, I swapped coolant with EI with reasonable success on my water-cooled Ducati, but I like the idea of a better fan just as a precaution. Riding in south Florida can be tough on bike engines (though all the Harley's don't seem to have problems).
 

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I'd do EI anyway, but I'm not willing to gamble that my factory fan will not fail when I least need it to. The Spal definitely moves a lot of hot air, much more than the factory unit does, Hank. If I lived in Florida I would do it straightaway w/o hesitation. Only downside is that you feel all the heat coming off the bike now.

Pete
 

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Mine is a late 2013 Duke 390, in India. I can confirm that the fan runs both ways - it pushes the air forward at speeds below 12 kmph and pulls in air at speeds higher than that. This was done to mitigate the complaints about legs getting roasted in slow traffic or at stops. I have never had an overheating issue, nor have I felt serious discomfort in slow traffic, so obviously the arrangement works. I too was very sceptical about this and thought that this was poppycock, but then............

By the way the Indian bikes carry a two year warranty.
 

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Point being if the factory wiring runs the fan both directions it could post a problem for a threaded or screw on fan. What retains the Spal blade?
That was exactly my concern also. I couldn't care less about which direction the air is flowing, just don't want to damage the new fan and/or the cooling system along with it.
 
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