temperature sending units?

My bike seems to be overheating, yet does not feel real hot. The gauge shoots up to all bars and blinking-red temp light on and this is when the fan kicks in. I was wondering if the fan kicks in earlier than full bar, maybe the gauge is getting a false reading. Ussually one can tell when their bike is running super hot and it does not feel this way to me. Should I try the sending first?

My fan kicks in with 3 bars to go, maybe this is your problem.

Had this problem at Chuckwalla with Kowekiller's SDR last session...
Pulled off the track..Temp gauge flashing..
No fan..Then it kicked on after shutting off and back on...
Intermittant at the fan switch..checked with ohm meter after he got home
and it showed open circuit...
Jumpered the fan to 100% "on" and changed out the coolant to water...
Still slowly creaping to top bars on the gauge...
Rear cyl. was getting hotter than the front cyl...
It's plumbed a bit different than the S.D. model btw...
Finally pulled out the thermostat...and the center stem had pushed itself
through the top of the metal housing...
In other words..
Bad thermostat...
Of course...dealer didn't stock the parts...Stat also only comes with housing complete...
What a rip off...anyone know where to get just the thermostat.???
Or if it crosses to another common bike or car even...????
No numbers on it to try and match up...

Have never understood why KTM fitted the OE 102.

Mine seems to heat up quickly if I get in traffic, I have only had the light come on once.
It was a 90+ degree day and I had to just barely idle up a steep paved road, cars backed up due to an accident.

I turned around and when I got some air moving thru the radiator the light went right off.
The fan had kicked on tho.