I see most people who’ve added a fan normally do so in front of the engine. There’s usually a mesh screen between the engine and the front diff/oil cooler. Most have it mounted there along with a toggle switch someplace and have it blow air on the head. The more popular fans it seems are the Spal fans. First I’ve heard of it mounted in front on the oil cooler. Then again whatever works right.
My 2001 KQ300 has a factory fitted fan just in front of the cylinder head. It has a rocker switch on the right hand handlebar. I believe that the fan will also switch itself on if the temp gets too high but I have not seen that happen.
Suzuki no longer makes the OEM fans. Those were the fans that ran on a temperature sensor which activated the fan on/off based on engine temperature. Since these fans no longer exist, people have made their own version using the Spal fans and a toggle switch. If your fan doesn’t automatically go on/off with engine temperature, the sensor might of gone bad.
I was looking for a cooling option as well. I had to replace my front seal and read that the motor runs so hot it brings the oil to pretty much a boil which destroys the rubber seals. I bought this machine used and didn't notice the sticker on the winch which states that an optional cooling fan must be used with a winch or snowplow mount.
I found a 12V IP67 (Dust and waterproof) fan made by Coolerguys (120x120x38) . It is rated at 157CFM and only draws 750 mA of current. It has been highly rated by guys who have installed them in front of the oil cooler rad on their motorcycles.
I installed it to the grill directly in front of the oil cooler rad and wired it directly through a switch to the battery. I used galvanized strapping and bent it over the grill. When I installed the fan and bolted it in place, the strapping clamped securely to the grill and has made a solid mount. The pictures show the logo facing outward which is wrong. I had to spin the fan with the logo facing the rad to blow the air through. I mounted galvanized steel screen to the open / front side of the fan to protect it from rocks.
The purpose of the oil cooler is to cool the oil with air flow through the rad. When a winch is installed, this air flow is blocked. This mod works and fits perfectly between the winch and the rad.
Harley Davidson used to have head damage to the rear cylinder due to heat. Indian V-Twin engines shut down the rear cylinder to reduce heat. They do this since the rear cylinder gets hotter than the front one, due to their orientation to one another. I'd install the fan on the rear & let the airflow from forward movement cool the front of the cylinder.
Do you mean relocating the rad and have the fan draw through the oil cooler AND blow air over the cylinder? I have seen this done but it requires more modification than I was willing to pursue. I wanted something quick and easy to compensate for the air flow restriction caused by the winch. This fan puts out 157CFM which is less than some fan setups I have seen but it really pushes a lot of air and only draws 750mA. I did a test and let my quad idle for 20 minutes with the fan on. The motor got hot, but nowhere near what it did before I installed the fan. These 300's don't like to be left idling for long but with the fan on it purred right along. I think it is a good alternative. Thanks for the input.
No doubt! Out in sticks now. Fan works perfectly. Towed a loaded trailer over steep terrain and through a few mud holes with no issues. Had to pull a Polaris Ranger out of a hole. Only way I could do it was in reverse in Diff Lock while winching. Fan kept the motor cool.