Hey gang ive got a 90' 3ln and ive noticed if i get too many red light in a row my temp gauge will get up too 3/4 i was just wondering what temp should the electric or thermo fan kick in. As soon as i get moving again the temp goes back down too half way.
Iv noticed the same thing with my 87 2kr,I dont think Iv ever seen the fan going. Does anyone know if its normal for the temp gauge to get up to 3/4 without the fan kicking in.It drops down to about half way when I get moving again. Thanks.
The thermo-switch can be removed and tested. It should be off at below 98deg and on above 102deg. Best tested with a decent thermometer and a multimeter using cooking oil in a fry-pan. I could not be sure but that would probably put the needle about 3/4 up the temp gauge to the red. Short out the two contacts on the thermo-switch to see if the fan runs first. (With ignition on)
Cool thanks for that, where would I find the thermo switch? Do I just follow the wires from the fan to it?
Thermo switch is on the thermostat housing, which you will find on the front RH side of the bike behind the radiator. Just follow the rubber pipe from the radiator to the engine. Note: the temperature gauge sensor is also located on the housing.
What are peoples thoughts on putting in a switch to manually turn on the fan even before the normal cut in 120 deg?
I was reffering to disconnecting the automatic start of the fan at ~120deg i was talking about having a manual override... To try cool the bike down BEFORE it gets hot enough for the fan to come on...?
Splice in a jumper switch across the thermo switch - that way the thermo switch still works if you forget to turn the switch on, and the fuse is still protecting things.
yeah doing it isnt a problem, but do people think its worth doing? Is it worth being preemptive about these things?
A lot of people do it; it's not a big deal. The question is more, do YOU feel it's worth it? Does your bike overheat? Does it get warm enough that you're concerned?
yeah it does get too hot, lol.. ALmost sick to death of all the problems associated with this bike, lol.. I've never had a prob with my gsx-r 750 hehe
My thermo fan cut's in at 3/4 and never overheats in traffic on a normal day up say 25*, but I put a manual over ride switch on my bike for when I take it for a thrash or if it's a hot day, it's easy to install. If your bike is overheating your bike maybe running lean or your cooling system may have a problem somewhere. old stale coolant, not enough coolant ratio to water I run mine at 50% 1:1 and replace it every two years, worn out thermostat, faulty fan switch temp sensor, faulty water pump, blockage somewhere and so on… I think the radiators on the FZR 250's are too small for Australian conditions.
im not sure if this was the best thing to do but i have removed the thermostat nd have hard wired the fan to the ignition switch, the bike used to over heat on a 20 degree day in traffic now in summer on a 40 degree day it sits on about a quarter for the temp.
Hi Bluefizzer2 The problem with removing the thermostat is the although the coolant will be cooler it is traveling to fast through some parts of the motor to actualy absorb to heat properly, this is usualy in the coolant galerys in the head. If it were me I would be seeking a new thermostat, if I still had a overheating issue I would be then looking at the radiator to see if it is gunked up. The next on the list would be the coolant pump. Tina
You can have overheating issues with a motor that has no thermostat, if the coolant is moving too fast to dissipate heat when it get to the radiator bit it will cook. Running with no thermostat poses a few problems. In a car, it means the heaer wont get hot. That sucks. The Main issue is that if theres no thermostat the engine will run cold. That will drastically shorten the life of the motor. The idea is that to reduce wear and friction your motor should be running at a high temprature. At a consistant high temprature. Cheers, Bob.
I would go along the that, get a replacement thermostat in there and get the temperature to stay at a reasonable temp all the time. In colder weather the bike is going to take a long time to get up to proper operating temperature.
Be very careful of cold seizes. Far more common with 2-strokes, but I wouldn't be surprised if you could do it on screamers like these.
I dont know that you would cold seize it. Thats an air cooled thing. Cold water on a hot motor, cold water shrinks the cylinder which then 'grabs' the hot expanded piston. With the water jackets on the FZR i would doubt you could get it to do it. What you need to check is that the sender in the thermostat housing for the fan is working. Its the one with the 2 wires on it. It will have live power on one side and its should then let power through once temp is up to a certain level. Say 70-80deg. Pull it out and rig something up so you can test it in a sauce pan on the stove. Or put an on off switch in the wiring there and make it manual. You just need to rememeber to turn it it. Id only have it off when the bike is frist started and warming up. And maybe in the deep of winter. I just pulled the motor out of the 2KR. Drained the water out of the thing, it holds 1000mls or water <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: --> No wonder they over heat. How does the water get from radiator down to the water pump on a 3LN??? Got a picture?? On a 2KR you could replace the bit where it uses the frame with some sort of finned tubing, run that across to the RH side of the bike and back to the left with some custom brackets to hold it. Not sure what you would find i nthe way of finned tubing in that big diameter. Maybe a transmission cooler or oil coooler would be that large in diameter. I know ive pulled out oil coolers that were in plastic tanked radiators. They are an extruded finned tube, but not in the ture sense of tube, you wouldnt be able to bend one, you would have to pie cut it and have it welded. Or if your really having issues, mount a dirt bike radiator low on that side. Bob.
