st1000 temperature higher ...

Hello to you, I realize that on my st 1000 1998, the temperature increases rapidly in traffic and this even if it is 20 '... when the outside temperature is cooler its less fast ... I should check What first? Because the coolant is ok ... the radiator? The fan works ... the thermostat ...? thank you to all of you!

If the needle never goes past (approximately) the one o'clock position, you have nothing to worry about.

I would check the fluid level at the Radiator cap, you might see fluid in the overflow tank but that is misleading.
A well known problem is at the small overflow tube leaving the radiator where it splits.
This requires taking off some of the Cowling.

+1 on both of the above, is that +2?
In colder weather they don't usually go above 1 o'clock, the fan should be in by then. If not it could well be the fan sender is shot. But I would check the level first. The only time mine was nudging the red zone was in 40 degree (Celsius....About 105f) heat and two up with luggage stuck in an Italian town centre. But I was warmer than the bike anyway so I didn't worry to much. The bike never went into the red though.
Hope it helps.
Upt'North.

The sensor will not sense the hot air in the cooling system. The radiator must have coolant. If the needle is swinging back and forth, you're lacking coolant. As mentioned, check level at the radiator cap.

Bush said:

If the needle never goes past (approximately) the one o'clock position, you have nothing to worry about.

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agree with Bush, we haven't been told enough yet to even suspect anything is wrong. On my normally working system "the temperature increases rapidly in traffic" just like the OP, who has only 15 posts, so maybe he doesn't know that "they all do that".

To the OP, if your fan comes on and the temp needle goes back down to about vertical, then there's probably nothing wrong. If the needle keeps climbing past 1 o'clock and into the upper range, then there's something to look into to determine the cause. The first steps in that process have already been mentioned, so I won't repeat them.

dwalby said:

agree with Bush, we haven't been told enough yet to even suspect anything is wrong.

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Thanks for making that point. Why go on diagnosing a problem, that may not exist, when we have so little information from the OP.

Bush said:

Thanks for making that point. Why go on diagnosing a problem, that may not exist, when we have so little information from the OP.

Click to expand...

Agreed we haven't heard exactly how high it goes.

As for checking the coolant...
I call it basic maintenance. Simply check fluids, but do it properly ie at the cap.
Any question with the cooling system makes it part of what one should check.
It's a little time consuming and so easily missed. Plus an original overflow tube will generally be split at the radiator cap by this point. Not good.

Ok... gang... I will be check all the point and I will be respond you!
thanks a lot again!!!