There is a small hole on the bottom(underside) of the water pump. If there is coolant leaking from here then your water pump is bad and needs to be replaced.

 

ok for the record i dont want to steal the thread. so sorry . my f3 fan wont even turn on! i was in traffic the other day and it shot sky high all the way to the red line. i was about to pull over and let it rest. will it really damage the bike? and im new to working on the bike myself what should i do to trouble shoot? i can work on it just dont know where to start when i first got the thing the fan worked but its not anymore. thanks in advance for any help

 

YES it can damage the bike. Aluminum heads can warp with extreme heat. I would start with the basics as to why it isnt working. i.e fuze and that nothing came undone while riding. Then check to make sure its your fan. The fan should run to the radiator on the left side. Unplug this(looks like a rubber boot) Stick a flathead screw driver in the rubber boot and turn your key to on, then tap the screwdrivers side to the frame. The fan should come on. If is doesnt then its your fan, otherwise its an electrical problem. i.e. fuze or wires.

 

follow this link

https://cbrforum.com/forum/stickies-...ng-fan-122988/

 

if/when you do wire up the toggle switch, wire the power through the ignition so when you turn off the ignition the fan shuts off, if you wire the fan straight to the battery then it will drain your battery if you forget that the fan is on.

 

FYI the fan's power already comes from the ignition switch. There are three wires coming from the ignition, Accesories/negative/+12V to Fan.

I'm pretty sure most thermal switches work off resistance. When the bike gets hot the sensor reads a certain resistance and "closes" turning on the fan. If you were to wire in a certain size resistor you might be able to "trick" the sensor into thinking the motor is hotter than it really is and turn on at lower temps. Have never tested this theory so I might just be talkin outta my *** lol.

 

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~~~~Cause when you own an older bike as I do , like a 98 CBR F3. When it's hot 🔥 & or 🥵 Humid outside. The bike tends to always get hotter than it should so it's a good thing to wore & wore a switch correctly to your fan & also Upgrade your coming fan if you can afford it so you're able to put the fan on whenever you feel the need that your bike needs extra cooling...........