Not getting a reply in the workshop so...

[Alex-RS]

I thought i'd be cheeky and post it in here...

Decided to do a coolant change on the bike yesterday because lately it's been gettin to around 78 degrees when i'm waiting at a few sets of lights in a row for example. I let the old coolant out through the bottom hose on the radiator, and filled it up with the bike on the sidestand, but now it's getting from 'cold' to about 50 in less than 2 minutes! I don't know if this is air in the system or what, but there is definately coolant coming out the top of the radiator into the engine when the bike is running. Desperately need help here as this overheating problem is playing on my mind.

[bikerchick82]

Sounds like you have an airlock somewhere...

S'cuse me for being dim but what bike is it?

To try and get rid of the airlock, take the cap off the radiator, run the bike for roughly 15 minutes, keeping an eye on the temp guage...

Do NOT rev the engine when doing this, just keep it on idle speed.

Keep topping up the fluid as needed and hopefully it'll sort itself.

You mention changing the fluid before as the bike was getting to 78 degrees....

Normal running temp is usually about 80 degrees so I'm thinking you changed it for no reason?

[Mr Nice Guy]

Yoikes, my gixer runs at about 78-85 on the move, stopped at lights, especially in this glorious summer we are having and it'll go as high as 107.

You sure you haven't just overfilled it and its coming from the overflow?
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Suzuki GSX-R750K4 ~ Mivv GP

[D O G]

Agree, 78 does not seem hot to me. My Gixxer ran at 82degrees as normal.

If the leak has only developed after you worked on it, most likely that you have made a mistake when reconnecting. You may have not tightened a clip properly (if they are jubilee clips), or tightened too much and crushed the tube inside. I remember crushing rad tube on a car of mine a few years back from over zealous tightening.

[Alex-RS]

Cheers lads. It's an aprilia rs 125, and according to aprilia 65-75 is operating temp, and anything over 75 and you should stop, as something is wrong. It used to stay at operating temp but a few weeks ago it was really bad, hitting 91 at one point. Btw, there isn't a leak as far as I know.

[Jai466]

Check the temo stat take it out and put it warm water on the cooker and then warm the water while the temo is in and it should open if not you need a new one.

Or As above post blead the system.

Or let the bike idle up to normal temp and see if the fan kicks in if not the by pass the fun switch and the temp will drop. If it dose then it could either be your fan or your fan switch.

[bikerchick82]

[Alex-RS]

[MinhDinh]

hmm my rs 125 runs at about high 60's and about 80 at the lights when i'm stopping. i have gotten to 90's a few times when traffic is really bad and once 99 or over 100. that scared me a lot but it was fine. any chance to move, keep the rs moving to cool it. seems to be okay to hit 80 imo.
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Hit the G spot.

[Alex-RS]

Thanks MinhDinh, I was hoping I would get another rs owner's input here.

Just took it out for a ride after doing another change earlier, this time doing what I can to stop an airlock, and the temp didn't rise above 72, so hoping it's all sorted now. Shame I got a random lack of power at one point, which went away by pulling over and simply turning it off and on again (had it before) no idea what that is, but, oh well.

[MinhDinh]

[bikerchick82]

[UrbanRacer]

start the bike, tilt the bike on its side till its nearly touching the ground and hold it for a min, then do it the other way. check the water level and do it again if it needed topped up.
That should clear any air in the system

ps. get a mate to give you hand holding the bike at those angles

[Bardeey]