My fan is not kicking on any more. I have checked all of the electrical connections and the fan does not work. Am I missing something here? I relieved the problem somewhat by removing the thermostat. After continuous hard riding, the oil light comes on. All of the fluids are at the correct level and fresh. Anyone have any ideas?

 

Removing the thermostat can cause an overheating condition, I would put it back the system is designed to have it. Is your radiator full of mud? Allot of times people overlook the simple stuff. Is your bike overheating at speed or at slow speeds? If it's at slow speeds it could be as simple as the fan is toast but I would look for voltage at the fan wiring when it's warm. Does it have coolant in it? The fan wont come on if there isn't any hot water to contact the thermoswitch that controls the fan. What does your oil look like? Is it nice clean oil or does it look like peanut butter? Have you been losing coolant? and have you had the engine apart lately? Take a test light or a voltage meter and look for voltage at the fan when you think it should be hot enough. May just be that simple..

 

Spin, Whew, are you out of breath or do your fingers hurt?? [img]i/expressions/face-icon-small-wink.gif[/img] Just reading it made me tired[img]i/expressions/face-icon-small-wink.gif[/img] That is a lot of good information you gave him[img]i/expressions/face-icon-small-smile.gif[/img]

 

And welcome to the forums Slideways[img]i/expressions/face-icon-small-happy.gif[/img]

 

Same thing happened to the wifes Raptor a few months after she took a spill into some water at Florence, OR on a night run. Over temp light would come on and the coolant resevior in the back would over flow. I just unplugged the fan and applied 12VDC to the connection. Fan didn't kick on. So I picked up one on ebay for 35 bucks. When it arrived I did the same thing. Applied 12VDC and the "new" fan kicked on.

I would start with the fan. It only takes a few minutes to unplug and apply voltage. If thats all good then work on what Spincycle suggested.

After looking at the fan assembly and seeing how easy salt water can get into the fan motor (through the propeller shaft), I picked up yet another fan on ebay. [img]i/expressions/face-icon-small-happy.gif[/img]

Good luck.

Vernman

 

Thnx, a long time ago I used to build radiators and coolers of all sorts.

 

Glad to find such helpful people rescuediver. All of my fluids are in great shape and the bike is very clean. I had done a complete tear-down about a month ago and have been adding some mods. Thanks for the advice vernman, something as simple as testing my fan with direct power was one thing I overlooked. Spin, thanks for all the ideas. I'll replace the thermostat, but I don't understand why it is there in the first place? My buddies YFZ does not have one and it runs fine?

 

I run my CR730 without a fan or thermostat. As long as I'm moving, it never gets above 180 degrees. I'm thinking of adding a fan back on though, it's a bummer to push the quad in the staging lanes.

 

The thermostat regulates the flow of coolant. I keeps it in the motor to allow it to absorb the heat, then transport it out to the radiator.

Redline's Water Wetter is a nifty cooling source. Along with a properly working fan. [img]i/expressions/face-icon-small-smile.gif[/img]

 

Taking out the thermostat is something that used to work on big american cars with big radiators, for themost part they were bigger than they had to be because size and weight were not serious issues. Taking a thermostat out of a newer high output, small radiator setup can cause overheating by not keeping the coolant in the radiator long enough to dissipate an adequate amount of heat. Your buddy can run without a thermostat but his cylinder head temps will fluctuate wildly depending on the amount of air passing accross the radiator and the temps outside. If he sits and idles very long the temps can sky rocket very fast. there are 2 main killers of combustion engines 1. heat 2. lack of oil.