Cooling fans

[bramfrank]

Having moved from a Concours to the FJR this year I am used to the cooling fans running when I pull in at the end of a run.

Kawasaki has the fans wired to run the fan if the coolant is above the temperature required to run the fans - they will usually blow for a minute or so then shut off.

If the FJRs been running 'warm', the fans will be running and will shut down with the ignition - they will come back on if the key is turned back on, so the thermostat is indeed calling for cooling.

I wonder if the fan shouldn't be be connected to the battery and not to the ignition as it is now?

 

[afterburn]

Why? A bit of heat doesn't hurt the engine and if it is not running, there is no further heating either. Even if the fan was running, the coolant isn't being circulated so the only thing you are cooling is whatever is in the radiator anyway.

 

[Geezer]

There doesn'r seem to be a lot of spare energy in the battery. I would expect the fans to draw it down pretty quickly if they were running without the engine turning.

 

[bramfrank]

If the coolant is all that hot I would have thought there would be circulation due to convection because the thermostat will be open.

And the Concours battery (not significiantly different capacity-wise than that used on the FJR) certainly never ran down as a result of the fan running.

 

[Leghorn]

After a hot run, why not just turn the ignition back on for a minute or so to blow some of the heat away?

 

[FJR1300]

If the coolant is all that hot I would have thought there would be circulation due to convection because the thermostat will be open.

Once the engine is shut off the engine no longer circulates the coolant.

 

[bramfrank]

If the coolant is all that hot I would have thought there would be circulation due to convection because the thermostat will be open.

Once the engine is shut off the engine no longer circulates the coolant.

Hence the term 'convection'

After a hot run, why not just turn the ignition back on for a minute or so to blow some of the heat away?

An option, certainly. However I was wondering if anyone had any insights as to why Kawasaki runs the fans and Yamaha does not.

 

[C&C]

Convection is not going to do anything positive to the heat of the engine. You still have plenty of residual heat that you don't have a chance of reducing (nor does it need reducing). All your gonna do is draw down the battery a little and cool the radiator water. Maybe if you're at four bars ('03-'05 models) and your fan just kicked in, you may want to keep the engine on until the fan cycles off but even that would be of minimal benefit.

 

[Cal24Master]

Having moved from a Concours to the FJR this year I am used to the cooling fans running when I pull in at the end of a run.
Kawasaki has the fans wired to run the fan if the coolant is above the temperature required to run the fans - they will usually blow for a minute or so then shut off.

If the FJRs been running 'warm', the fans will be running and will shut down with the ignition - they will come back on if the key is turned back on, so the thermostat is indeed calling for cooling.

I wonder if the fan shouldn't be be connected to the battery and not to the ignition as it is now?

Your Connie had carburators. The fan continued to run to keep the float bowls cool so it wouldn't vapor lock. My old Katana did the same thing. With fuel injection it is not necassary. Welcome to the 21st Century!!!

Tom

 

[Bounce]

Gold Wings turn off the fans with the ignition, too. Less apt to kill your battery that way.

 

[Hoog]

Your Connie had carburators. The fan continued to run to keep the float bowls cool so it wouldn't vapor lock. My old Katana did the same thing. With fuel injection it is not necassary. Welcome to the 21st Century!!!

My Triumph Sprint St was fuel injected, and the fans would run after shutdown when it was hot enough. They are a British company though, so the 21st century crack may apply.

 

[FlyingLow]

It's up to the whims of the engineers, it would seem.

 

[Centerline]

After a hot run, why not just turn the ignition back on for a minute or so to blow some of the heat away?

+1 on that. When I park at home in the summer heat, I have fans on the garage floor in front of the bike to blow some cooling air for about an hour. It is nice to have a cooler bike should I go for another ride sometime soon.