Temperature gauge probs?

[Bundybusa]

I have previously always noticed my temperature sitting quite static at just below half and not moving. It now seems to reach that same level but steadily drops down to quarter then rises back up to just below half. It does this over and over, and is not just a "once off, here & there" occurence. I am wondering if my gauge may be dodgy or if the thermostat is opening and closing way too often. Any ideas or similar experiences?

[fasterfaster]

Check coolant level at the radiator cap ................ not the over flow bottle. For it to be hot then go that much colder (by the gauge) like that it almost sounds like it has air around the sender (air lock) Could be stuck thermostat.
It is normal on start for it to climb to op temp and then drop back as thermostat opens ....................... but it shouldn't keep cycling so radically once operating temp is reached.

[alpal]

Yep mine does the same when cruising down highway or at least this is the only time I have noticed it seems to get too cool and thermo shuts till it gets up to normal temp again thermo opens again and cycle repeats itself. Never see it happen in traffic or fanging it.

[G-MAN]

Yeah mine does the exact thing,checked coolant level and have bled the system ,but made no difference the needle still fluctuates while travelling on the highway

[Bundybusa]

I might check the water level at the radiator as suggested by Pete. I am now also owndering whether it has always done this but I have never paid much attention before.

Thanks for your replies guys.

[Vellaterra]

I have noticed the same, as I travel the F3 frequently. I tend to think the gauge is OK. I think its the T/Stat adjusting itself according to ambient temperature. You will notice the fluctuation is more obvious in winter. The T/stat closes and allows temp rise then when it opens, the radiator is already quite cold and the temperature drop is quiet sudden, the needle drops, then stablises, then as the T/stat closes the tepmerature rises again.

During this last winter I posted a concerning comment on this very issue without much feed back. I came to the conclusion that not too many people actally ride in the thick of winter. But thats my opinion...... I am an all year round kinda rider.

To prove my point, next winter take your Busa out on the freeway on a very cold night. You will notice the temp drop almost straight away. I found when the ambient Temp is around 5*C to 10*C, you will notice that the temp starts to fluctuate and you will see the needle move. I have been almost tempted to wire up an electronic Thermostat to get a true temperature reading of the engine whilst riding in such harsh temperatures.

[Bundybusa]

Went for another ride yesterday with an ambient temp of around 36 degrees. The gauge did not fluctuate at all.

The other week when the gauge was going up and down, the weather was raining and mid 20's.

So I think I will put it down to the Thermostat opening and closing as suggested. Nothing scary happening to be worried about thankfully.