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Hi, When my bike is hot and the cooling fan is on, if I shut the bike off using the kill switch but leaving the key on the fan shuts off. Is this normal?:|
 

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Yes, the Tiger1050 cooling fan only runs when the engine is running and the temp is high enough for the fan to be turned on. Also, Mr. T does not recommend shutting off the Tiger using the kill switch except in emergency...I have not yet heard of anyone finding out what problem this causes by continuing to use the kill switch for shutting down the engine.
 
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Yes, the Tiger1050 cooling fan only runs when the engine is running and the temp is high enough for the fan to be turned on. Also, Mr. T does not recommend shutting off the Tiger using the kill switch except in emergency...I have not yet heard of anyone finding out what problem this causes by continuing to use the kill switch for shutting down the engine.
I would imagine it is the belief some hold, that continued use of the kill switch will bring about its destruction. Many believe that the switch assembly is marginal at best and not suited for constant use. This belief spans all makes of bikes.

Interestingly, the MSF teaches use of the Kill switch as a habit to get into.
 

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Why would you want to jumper out the fan to allow it to continue running once the engine is off? Cooling down the engine quickly is not that important.

The ambient heat loss with engine off is plenty to cool it down in a reasonable time. Some automobiles have this feature but they have much larger mass to cool and much larger batteries to handle the fan for a few minutes.


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There is heat built up in the heads and block that will take the coolant other parts of the heads to higher temps than they can reach with the thermostat/fan engaged. This wisdom, if it is, comes from cars but that science should cross to bikes except maybe two strokes. Going out on a limb here but I would think that the anemic battery situation would cause the mfr. to err on the side of reliable starting so long as the cracks in the head hold off.

The cooling fan is fused at 15 amps and the master fuse is only 30 amps to get that in perspective. It wouldn't have to run with the engine off for a very long while to take the edge off of the battery. I installed a 18ah lithium ion battery and I might mod my bike and take the fan off of the ignition switch to achieve this feature. Then again, maybe not.:smile2:
 

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True: there are places in the block and head where the temperature is much higher than in the coolant itself.

If the fan runs for a few minutes after shutdown it would lower the temperature of the coolant in the radiator, but given the lack of circulation (engine not running) I wonder how much that would translate to lower head and block temperature.

On the flip side, lowering the head and block temperature too quickly could also have detrimental effects. My opinion is we're unlikely to do better than decades of engineering and experience. If it works why mess with it unless there's a compelling reason to modify the design?


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Some Numbers to try to see clear.

Fan consumption is just 4A under 12V, say 50W less than lights which are in use during engine start :) no problem for the battery.
Just 30 seconds of fan's working to decrease the coolant temperature of 2 ° C (engine off).
30 seconds is the length of the time delay that I chose, it's enough.
When fan is working and engine stop it remain a little coolant flow (calorstat is still open) by thermosiphon principle.
So, i 'm not trying to say that it is essential but simply better... remember before ECU on board, fuel injection, every motobike with water cooled had a thermostat fan coupled
no one then to say it's better to stop fan with engine.
Engineers do not always work in the customer's interest but above all to respect the specifications and make money ! What do you think about planned obsolescence :)

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Stéphane.
 

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If the fan runs for a few minutes after shutdown it would lower the temperature of the coolant in the radiator, but given the lack of circulation (engine not running) I wonder how much that would translate to lower head and block temperature.

Not a great deal but it would certainly register. Convection would carry some of the water slowly into the engine but here again I don't think it would do much.

My opinion is we're unlikely to do better than decades of engineering and experience.
The decades of experience and design is in favor of the fan running on after shutdown. I have not done a survey but all the cars with an electric fan have that design. At keast I have noticed it on all my cars and I drove rentals for years wen traveling on bidness. I think I mentioned that the bike people might be driven to this design out of consideration for our weak batteries.

Your point is certainly well made and taken with regard to "if it ain't broke...". The trip[ple has a superb reputation as a long lived engine as designed.
 

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Some Numbers to try to see clear.

Fan consumption is just 4A under 12V, say 50W less than lights which are in use during engine start :)

before ECU on board, fuel injection, every motobike with water cooled had a thermostat fan coupled and no one then to say it's better to stop fan with engine.

At least some cars still work that way.

Engineers do not always work in the customer's interest but above all to respect the specifications and make money !

And they have crossed motivations such as "reliability to start" vs lower coolant a few degrees after shut-off.

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Stéphane.
I like the idea of running the fan till the rad is cool enuff to shut off the fan. That design would serve to keep the coolant at a more even temperature if it were only a few degrees.


TRY SOMETHING. Run you bike up a long hill and note carefully how many lines you show for the temperature gauge reading. At the top of the hill turn of the engine and let the bike sit for a few minutes and turn on the key and see if the temp has gone up. I think you will be surprised at how much it has increased but I haven't done it with the Tiger. Cars will boil over when sitting if the coolant is low or the system is marginal in that situation. I never turn off my truck engine right after a pull, such as pulling off the freeway, as I can sit and watch the engine temp climb to scary in just a few minutes. I always run the engine for a few min and the temp stays down.

BUT those words of "if it ain't broke..." are still ringing in my ears.

Thanks for your comments Stephane
 

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Running a test is a great idea. Place thermocouples in the radiator, block, and head. Run two scenarios. Monitor and record temperatures for several minutes and see what the difference is. Crowdsource interpreting the data here - lots of experts who could weigh in.


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