Reasons I've ruled out the thermostat are:

1. It worked fine when I tested it in boiling water

2. Taking it out only helped the bike run cooler

3.A problem concerning a removed thermostat would also be present when idling/revving in place.

 

Taking out my t-stat only helped in traffic. It doesn't overheating at a stand still now.

You're right about water wetter for lubrication. But corrosion is only due to the impurities in anything but distilled water. You could run distilled water in a system longer than antifreeze, and it will never cause corrosion. Water wetter though, as you said, is necessary for lubrication. You can get it at a local auto parts store too. :-)

 

i went to our local bumper to bumper and autozone to get water wetter and they didnt carry it i had to order it from jegs but that was about a year ago. as for your heating problem you said it cools down when you pull in the clutch???? how long does it take to overheat initialy . also was anything changed on the bike befor this all started and are the cooling finns clean . nodebrea in the front of the radiator ??

 

Run coolant, not plain water. It will reduce corrosion and raise the boiling point of the fluid. Corrosion will come from dissimilar metals also, Think about the sacrificial zinc anode on a boat.

Faster flow should bean more heat transfer by keeping the heat driving force at a maximum.

We have to assume that the air moving through the radiator should help keep the engine cool. That is its design and that is how everyone elses works.But it doesn't, so maybe there isn't enough flow of water. You see it moving, but is it moving enough? You see it flowing, but is it flowing enough and to the right places?

My guess is a f***ked up radiator, or for some reason the water pump isn't pumping that well, maybe the impeller is going bad (not sure that this is possible). Other than that is the suction side of the radiator hose collapsing with higher revs? Again, I don't know if this is possible, but it has happened to me on cars where the hose got sucked closed.

Good luck, keep us posted.

 

Thanks for the replies so far guys. I'm thinking the radiator too. I'm going to pull it and take it to a shop today and see what's up.

And yes, it cools down when I pull in the clutch. Or when I'm in neutral. The water is flowing in the radiator, but it's possible not enough. I'll find out today

Thanks again guys. I'll keep you all posted.

 

Cools that muchbetter at what I assume to be lower revs???? I'm guessing hoses now although the radiator may not be 100% since it is 8 years old. I'd still change hoses, and make sure that the suction side has the coil (to stop collapsing)in it if it is supposed to.

Let us know.

 

Fishfryer, I'll check that suction hose. I don't remember there being a coil there (forgot to check) when I pulled the radiator. I find out if the rad is ok tomorrow. Also, I put new copper plugs back in, instead of the iridiums (they were the same heat range). I took it out for about 40 mins today before I pulled the radiator. It's not a problem when in gear (like you were saying FF). It's a problem with higher revs. Anything over 5K and the bike would heat up. Upshifting and lowering the revs cooled the bike right off. I feel like I'm narrowing it down.

 

Well, still didn't get the rad back I willtomorrow morning. But there is no spring in the lower hose. Is there supposed to be? And would that cause my sudden overheating issue. I was fine one day, overheating the next. This wasn't gradual

 

im having similar problems with m 99 f4. i've madea patch in the radiator with jb weld due to a header flange puncturing itandcurrently doesnt have a t-stat(in the process of replacing). I noticed coolant bubbling out of the main rad hose on the right while sitting on it. also it occasionally smokes a bit, looks like under the gas tank somewhere i cant pinpoint it. reading through my manual possible cause could be i need an oil change, too much coolant(im going to flush it when i get some time), perhaps not having a t-stat (it says if its sticking open it could cause overheating). if anyone has any other suggestions let me know.