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I have used the OEM fan in all three of my bikes without any battery discharge problems running the stock electrical systems. The problem has always been with the 85 C OEM thermo-sensor triggering the fan to run way too much. I solved this problem by using a higher temp 91 C thermo-sensor, resulting in fan operation only when really needed. Note that the newer OEM fan kits are now being supplied with 95 C thermo-sensors.

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I have used the OEM fan in all three of my bikes without any battery discharge problems running the stock electrical systems. The problem has always been with the 85 C OEM thermo-sensor triggering the fan to run way too much. I solved this problem by using a higher temp 91 C thermo-sensor, resulting in fan operation only when really needed. Note that the newer OEM fan kits are now being supplied with 95 C thermo-sensors.

my 06 probably has the 85C thermoswitch(PO installed) and i had to install a on/off(ground interrupt) switch or my battery wud discharge when woods riding...slower technical stuff where the fan wud run constantly and sumtimes run for ~30 seconds after the bike wus shutdown which wus totally useless.

everything i've read indicates the 95C thermoswitch solves this but the on/off switch is nice also 🙂

:banana:

Edited by Kenzo
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I have used the OEM fan in all three of my bikes without any battery discharge problems running the stock electrical systems. The problem has always been with the 85 C OEM thermo-sensor triggering the fan to run way too much. I solved this problem by using a higher temp 91 C thermo-sensor, resulting in fan operation only when really needed. Note that the newer OEM fan kits are now being supplied with 95 C thermo-sensors.

+1 I changed both my bikes to the 91 degree sensor

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I know a couple guys that put high volume computer fans on their bikes. They cost less than 15 bucks, and supposedly move as much air as the KTM factory fan. I think you have to use a switch with these. Might be worth looking into.

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I have used the OEM fan in all three of my bikes without any battery discharge problems running the stock electrical systems. The problem has always been with the 85 C OEM thermo-sensor triggering the fan to run way too much. I solved this problem by using a higher temp 91 C thermo-sensor, resulting in fan operation only when really needed. Note that the newer OEM fan kits are now being supplied with 95 C thermo-sensors.

Thanks much for the information -- I've been thinking about getting a fan for my '07 525. Would you happen to know the part # for the fan with the 95 C sensor?

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Thanks much for the information -- I've been thinking about getting a fan for my '07 525. Would you happen to know the part # for the fan with the 95 C sensor?

It is my understanding that all the new OEM fan kits now come with the 95 C sensor. Check with Chip Munn at www.munnracing.com.

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Go to your local computer store and get the Delta AFB 0912 SH, it's 1.5 inches thick, draws .7 amps vs. 2 amps for the KTM fan, costs $12 vs. $139.99 for the KTM fan. You don't have to install a thermostat, just put in a switch, and turn it on when the bike starts to get hot.

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I know a couple guys that put high volume computer fans on their bikes. They cost less than 15 bucks, and supposedly move as much air as the KTM factory fan. I think you have to use a switch with these. Might be worth looking into.

That's what I did and haven't had any oveheating probs. My bike did boil a couple of times before I put the fan on, but it would only do it on the street, at a stop light in summer time.

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It is my understanding that all the new OEM fan kits now come with the 95 C sensor. Check with Chip Munn at www.munnracing.com.

Yep -- I stopped at the local dealer today and found that the fan kit for the '08 -'10 EXC has the 95 C sensor. Unfortunately, I have an '07 525 and the fan kit for that year comes with the 85 C sensor. I could order a separate 95 C sensor, but it's $59 on top of the $120 for the fan kit.

Interestingly, the fan for the '07 has a rather large shroud, which itself can block some air flow and cause the fan to run more often. The kit for the

'08-'10 models just has a metal bracket for installation and no shroud surrounding the fan body. Anyone know if you can adapt the bracket to fit on an '07?

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Go to your local computer store and get the Delta AFB 0912 SH, it's 1.5 inches thick, draws .7 amps vs. 2 amps for the KTM fan, costs $12 vs. $139.99 for the KTM fan. You don't have to install a thermostat, just put in a switch, and turn it on when the bike starts to get hot.

Thanks for the information. How did you mount the fan -- like pterry above? Do you have a pic?

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I went super budget. I used thin angle aluminium, I bought it at home depot. Then I used industrial two sided tape. The angled aluminium is just enough to keep the fan off of the radiator but close enought to pull air through. It's worked great for over a year with no problems.

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Yep -- I stopped at the local dealer today and found that the fan kit for the '08 -'10 EXC has the 95 C sensor. Unfortunately, I have an '07 525 and the fan kit for that year comes with the 85 C sensor. I could order a separate 95 C sensor, but it's $59 on top of the $120 for the fan kit.

Interestingly, the fan for the '07 has a rather large shroud, which itself can block some air flow and cause the fan to run more often. The kit for the

'08-'10 models just has a metal bracket for installation and no shroud surrounding the fan body. Anyone know if you can adapt the bracket to fit on an '07?

Many import autos use the same thermo-sensors. For instance the sensors for the '84 BMW 318i are the same and are available for as low as $12 online. NAPA stores usually stock these for about $20. If the stock sensor is 85 C, buy or order a 91 C or 95 C unit.

The shroud on the older fans causes no problems at all and actually increases the cooling efficiency when the fan is running. A plus is that the RFS fan kit, for some reason, is much less expensive than the newer fan kit.

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Many import autos use the same thermo-sensors. For instance the sensors for the '84 BMW 318i are the same and are available for as low as $12 online. NAPA stores usually stock these for about $20. If the stock sensor is 85 C, buy or order a 91 C or 95 C unit.

The shroud on the older fans causes no problems at all and actually increases the cooling efficiency when the fan is running. A plus is that the RFS fan kit, for some reason, is much less expensive than the newer fan kit.

Thanks for the information about the auto thermosensors -- I'll check it out. Using a computer fan seems like an inexpensive alternative, but I wonder about the durability.

Glad to hear that the shroud doesn't affect the cooling efficiency of the older fan kit. You're right -- the RFS fan kit is less expensive than the newer kit.

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That's what I did and haven't had any oveheating probs.

The way you've attached your fan is going to cause problems. Eventually the fan will wear through the radiator tubes causing a leak. Fabricate some brackets to stand the fan off or mix up some plastic epoxy and mould it to the radiator where the fan contacts it to prevent wear.

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The way you've attached your fan is going to cause problems. Eventually the fan will wear through the radiator tubes causing a leak. Fabricate some brackets to stand the fan off or mix up some plastic epoxy and mould it to the radiator where the fan contacts it to prevent wear.

The fan doesn't touch the radiator.

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