I don't want to sound like an idiot but does a 93 CBR 600 F2 have a thermostat? Or is it supposed to have one?

 

yes it does, and it is suppose to have one. If it doesnt, I'd suggest putting one in. Without it, your bikes temp will be all over the place. The thermostat also controls how long the coolant stays in the radiator to cool off, so if there isn't one in the bike, theres a good chance of overheating.

 

Thanks! I think the one that's in it right now is stuck closed. The bikes Radiator fan isn't working but it still gets really hot, really fast!! Also, Honda wants $500 for a fan, is there anywhere else I can get a "New" fan like orielys or autozone or something? Or do I have to get one from a bike place or ebay?

 

these bikes get really hot really fast if the fan is not working. If you let the bike idle, it will probably get overheated within 5 minutes without a working fan. I would lean towards the fan being the issue and not the thermostat until you fix the fan.

The first thing I would do is find out why the fan is not working. Make a set of jumper wires and run them from the battery to the fan. If the fan works, then you probably have a bad temp sensor or fan motor switch as its called sometimes,( I think its on the lower left side of the radiator on that bike) If the fan doesn't work, then replace the fan. Ebay should be a good place to a good used fan for around 30 bucks. Im not 100 percent sure how to check the temp sensor, but there should be a resistance check on it. I'd suggest picking up a service manual for the bike.

If you get the fan working correctly and it still gets hot, then dig into a coolant flush and thermostat check/change. But remember, it will get hot quick unitl the fan kicks on. Any time you stop, the temp will climb very fast until the fan comes on, which will keep it from climbing any further, but it usually won't cool back down until the bike is moving.

having said all of this. If the bike is getting hot while your driving it at a good speed, then you probably have a plugged cooling system or as you said, the thermostat could be sticking. But the most common issue is a bad temp sensor.

Also, there should a fuse that controls the fan as well. might be worth looking into.

 

I tested the wires right before it gets to the fan with a test wire and it is getting power so I know the fuse, power, and sensor is working. And yes it does get hot while riding. I think it is a combo of both! My biggest thing is that I don't want to risk buying a used fan and it be bad once I get it. I would prefer to get a new one. Would you know where I could get one?

 

Im not sure where to get a brand new one other than a dealership. Im sure there are places out there, but I wouldn't be afraid of buying a used one and saving a few hundred dollars. If you buy from a reputable ebay seller, you shouldn't have any issues. Fans are one of those items that can be had cheap because they don't fail all that often.

How did you test the power to the fan? I believe there is a constant hot going to the fan at all times, then when the temp switch is triggered, it completes the ground side of the circuit. So even though there may have been positive power, it may not have been the completed circuit, and the bike would have to be at the correct temp for the fan to kick on, which is actually pretty high. I would still bench test the fan before buying a new one.

Does it only get hot while your sitting, or even if your riding at speed? All bikes will climb in temp really fast. For example, you may be at normal temp then come to a stop light. If your there for more than a minute, depending on how hot it is outside, the temp will climb into the red within that minute if your fan is not working.

I'm not saying theres not something else going on, but you know the fan is not working, which is a very important part of keeping these bikes cool, especially since the cooling systems are so small, that I would fix that first, then see how the bike reacts.

Sorry I can't be more help with buying a new fan, I honestly would buy a used one without any worries. You may want to post in the F2 section of this site as well. I'm sure more members in that area would have more knowledge of common things to check.

 

When I tested it the needle was at about 3 quaters of the way up to the red line. It wasn't over heated but close. When i turned on the key, it got power. After I let it cool down, I turned on the key, no power to the test light. And yes, it will get hot while actually riding at speed. I got about half a mile from my house and had to shut it down. I was cruising at 65MPH. I live right off of a main highway. I'm going to tear into it next weekend and see what I can find.

 

Your probably right then. The thermostat could be stuck shut. But I would also flush the radiator when you check the thermostat.

As the bike starts to get warm, does the radiator get warm too? Or is it cold?
Does the upper radiator hose get hard, as if pressure is building up too much?

heres an online service manual for your bike. You can download it and save it to your computer. It opens as a pdf file. Its a big file, so it may take awhile for it load. its over 50mb.

http://hondatech.info/downloads/Moto/CBR/

 

I haven't checked the hoses or felt the top. I will check that today! Thank you for the S.M! I will definately read through that!

 

This isn't the solution to your problem, but once you get those other items fixed you might try running water wetter in your coolant. I run it in my car and bike and I can tell the difference.