radiator fan


Im into mounting a fan on the radiator and if someone already did this, I only wonder of the best location to attach it

since all single fan bikes use it on the left raditator, this probably means its the hotter of the two

so the upper, middle or the lower end of it?

mostly I ve seen bikes in the middle and lower position

is there any aftermarkt or oem kit wich would represent the best mount location?


not too sure about location, but ive heard dc computer fans will work, ill be doing this mod soon i think, cause i have unabiker rad guards, theres really only space left in the middle to mount it, so ill prob put it there.

let us know how you go

cheers - Brett

KTM do a kit but is is expensive,There was a rad converted on EBAY UK dont know if it is still there

Im into using a computer 12vdc fan

made housing fo it and dressed it in antivibro bicycle inner tube

I too found some info on TT, guys use it with no problems, even in wetter conditions

Ill probably make it easy detachable, because pressure cleaner is probably no friend of delicate electric innards

since I dont have battery (wr400), ill attach it to the wires of removed horn and controll it through horn button

yeah was just thinking that the 400s run on straight AC

im thinking of trying to find a fan that runs off 12v AC

or better yet getting a rectifier happening

just read your old thread rich, im interested in how you implemeted the battery into your 400. can you shed some light on what you did?

cheers - Brett

Brett, go to my dual sport kit page here: http://www.farplaces.com/dual.htm

Check out the wiring diagrams section. This should explain a lot. The page is a work in progress but you should be able to glean something from it.

Dave, I don't have any fan photos but all I did was safety wire the fan in behind the Devol radiator guard in front of the radiator. So far, it's holding up very well.

One thing that's puzzling me- you say you don't have a battery. Is your lighting circuit rectified? The 12v DC fan won't work on AC.

I just managed to connect the fan, first to the battery charger to check functionality and than to the ex-horn wires on the bike and it worked normal when I pressed the horn button

engine, naturally, has to run

fan is 12V DC without a doubt



afer installing home made rad guards and completing installation to the bike, I noticed, that left rad is useless for fan mount, since it has a water tube fitted on top middle and is lined towards the cylinder, so no place for fan can be obtained.

However, I should probaby manage to squeeze it somewhere behind the right one.

I think KTM's have coolant cap on the left rad and probably that means its the hotter one, so since yama has it on the right, it should be just fine for the fan.

I am eagerly watching this thread for someone to show that they have successfully installed a fan and details/pics on how they did it.


when I installed my GPS on my Wr426, I simply used a cheap bridge rectifier to get 12vdc. The AC is regulated already, so u just need to rectify it. The bottom of the top tripple clamp works as a good heatsink.

Here's a brief write-up on my radiator fan installation.

I can see, there was no need for a rectifier, same for me

just plug the DC fan to any constant source and it'll work

i did notice though, that original bike fan rotates faster

5valve, if you are replying to my post, I do have a rectifier on my bike. The fan is a DC fan. The power is taken from the battery.

ah, OK, have read again few previous post

not sure why DC fan is working when connected to the horn wires on my 400 without using AC DC converter

I know tham my previous bike had DC current (ktm supercomp) but the blue one? no info on that in the book, should get it measured with a multimeter

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