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Discussion Starter #1 (Edited)
After trading my 02 400ex for an 02 big bear 400; i noticed it had an oil cooler with a fan connected to a thermal switch... this got me to thinking my timberwolf might could use one.

After taking some slow trails one day; the fan came on just as I was exiting onto the road. Seeing as that I would probably be riding slower with my girl along with her riding the wolf, I scoured the web looking for a cost effective solution to keep it cool (just in case)

I found a 13$ china 12v temperature controller
Mini Digital Temperature Controller AC 110V 10A with 12V DC Power US Seller | eBay

and a $26 IP55 rated (rain proof) case fan that moves more than enough air.
120mm 25mm New Case Fan 12V 175CFM Ball Brg Waterproof to IP55 4 Screws 325A | eBay

I set the temp to turn on at 212F (100c) and it has a hysteresis of 8 degrees (adjustable)

The bracket was made from 3/4x1/8 angle iron cut in half and bent to accommodate the fans mounting holes.

I wired power from the tail lamp since my low beams are disconnected (swapped out for LED's on the high setting) and the controller can be powered off with the switch.

The control was mounted into a box (not provided but can be purchased at radio shack) and mounted that into the air box.

The thermocouple was JB welded to the base of the block (pictured) near the jug, but not on it. I was going to mount it in the back like the big bear, buuuutt, I had no idea when the BB thermoswitch activated, so my best guess on temp was at the base. (not too hot, not too cold)


thermocouple location

fan front

fan back

FLIR camera showing the temperature gradient from the top of the head to the crank case after warmed up to normal riding temp.

Premium Member
1,423 Posts
Just wondering why u mounted the controller in the air box? Nice set up and pics.
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