This is a new toy to me. For those who have removed their cooling fan(Todd), here is a temperature strip I found at Dennis Kirk.

 

Now that is slick! I may just get me one of those. I wonder what the acceptable range is for our motor?

 

car engines are designed to never exceed 210 degrees. most cars the fan kicks on at 208 (those with an electric fan) and runs full speed till the coolant is brought down to 190 degrees. I would imagine since the antifreeze used is the same that the ideal coolant temperatures would also remain the same. The only time you will ever really catch the cooling fan on a car to come on is at idle or when the ac is turned on. Due to how little of fuel is burned in these motors the overall temp may never exceed 195 degrees under normal conditions

 

It also depends on where the temperature is measured. On my ZX9R the fan came on around 205. The thermostat seem to keep it around 160-180. On my CBR600F4i, the fan came on at 220, the thermostat kept it around 170-180. At 150, the Fuel Injection on that bike went to full rich to cool the motor and the temp warning light came on. That never happened. I don't know what the KLX is set for.

Most newer cars built after 2000 need higher exhaust temps for the new generation of catalytic converters. 4 cylinder engines in particular, were flipped around so the exhast header was closer to the cat (on Toyotas and Hondas at least).

Minimum operating temp is always around 100. You want it between 150 and 170 for most use, and 200-220 is a good limit.

Also measuring temperature on the outside of the cylinder head may not give the same results as measuring the water temperature.

 

What we need is for someone that still has the fan to put one of these on and then look at it just as the fan comes on. Then those of us that have scrapped the fan would know when (if) we are getting into the danger zone.

 

You could wire a simple light bulb indicator and connect that to the fan power connector that you disconnected when you took the fan off. When the light comes on, you know that's the temp when the fan would be kicking on if was still attached.

 

You could wire a simple light bulb indicator and connect that to the fan power connector that you disconnected when you took the fan off. When the light comes on, you know that's the temp when the fan would be kicking on if was still attached.


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Ding, ding, ding, we have a winner! That is actually an excellent idea. I'm keeping my fan and waiting on increaseing the tank size. I've dug out of mud a few weeks ago and watched the fan come on... and then the engine temp light come on next.

 

Yep. Plan to do that if I don't get around to putting on a smaller fan. My fan never came one even with extended idle but it is winter. Summer may be a different issue. There's plenty of room for a small 12v fan in the lower right quadrant of the radiator even with the IMS tank.

 

When I took the driving test last Saturday, one of the guys had a Suzuki DR-Z 400 and he had a dead battery, so he jumped it and got it started 15 minutes before the test started. So he left it running while he went into get his application, well we were all standing around talking and all of the sudden we noticed his bike was getting really hot, so hot in fact that the water in the recovery tank was boiling. So we shut it off so it wouldn't do any damage. His bike has no fan, so I really like the idea of a fan. One of these days I'll have to just start it in my driveway and let it run and watch/listen for the fan to come on. So far with 650 miles on it I haven't notice the fan yet. Couldn't he add a fan to prevent this from happening? I suppose in the bigger cities with a lot of stop and go, and just stopped traffic this could pose a problem.

deej

 

I have heard my fan come on, probablyl about 5 times when I was stuck in some mud trying to get out of a valley with mud on both sides of me. This is the only time I have noticabley heard my fan come on. And outside was probalby about 65-70 degrees.