In March of this year I spent two weeks riding off road in Morocco. A concern that I had was cooling of the engine as Morocco can get quite hot. Not being a Dakar type rider my speed along rough roads would not be too fast and thus the air flow through the radiators would less than a more experienced rider. Also into the mix was that I had put on an Aqualine 28L petrol tank. From the picture you can see that it wraps around each radiator and thus the air flow is quite diminished.
So I thought that a radiator cooling fan would be a good idea. Now as the bike is a DRZ400E the existing plumbing prevents installing the stock cooling fan that the S model is equipped with. Through some an Internet investigation I came across an Italian company that manufactures automotive fans. This is the link the UK distributor: http://www.spalautomotive.co.uk/. Here is the link the specifics on the fan that I purchased:
This fan is more compact the stock DRZ400S cooling fan, will fit behind the right side radiator and is small enough to not come into contact with the Aqualine petrol tank.
Using the Unabiker radiator guard protector provided a pair of mounting points but a third was required.
Starting with a joist hanger bracket I was able to fashion a bracket that would attach to the top of petrol tank mounting point that is welded to the frame.
Lastly a toggle switch was wired in to manually turn the cooling fan on or off when circumstances required.
When I purchased the bike I had TrailTech Vapor installed. From this I could keep a watch on the coolant temperature. I can say empirically that the fan reduced the engine coolant temperature by 10C to 15C. The coolant temperature never went above 93C with an ambient air temperature of 26C when riding a slow crawl.
Total cost of the parts was around £60.00 GBP. The bike is a 2009 model.